If you looked very closely, there was a fist pump. But you had to look very closely and catch it very quickly, because Steffi Graf’s celebration of her 1988 calendar-year Grand Slam was more appropriate to maybe a forehand winner in the first round at Amelia Island.

In some ways, that victory over Gabriela Sabatini in the US Open final, which made Graf only the fifth singles player in history — man or woman — to accomplish the feat, was simply quintessential understated Steffi.

But under the glare of TV lights and no doubt the heat of the moment, the 19-year-old quickly revealed that she looked rather joyless for a reason.

“I feel at the moment very hot,” Graf said as she peeled off her warm-up jacket following the match. “Otherwise, I’m feeling very happy to get the talk about the Grand Slam over with. It’s a great relief. Now I have done it, so there’s nothing else you can tell me I have to do.”

It is impossible to tell if Serena Williams is feeling the same burden as she enters this US Open attempting to complete the first calendar-year Slam since Graf and tie Steffi’s total of 22 major titles. But as Serena struggled in Toronto, smashing her racket in frustration during a semifinal defeat less than two weeks ago, and continued to labor last week in Cincinnati en route to the title, the pressure of the moment cannot be denied.

After instructing the media at Wimbledon not to ask her about “the S word,” Williams revealed last week that she was going to tell her agent to minimize all outside activities leading up to the Open.

“I’m really trying to stay away from stress and stay away from press …” she said. “I don’t necessarily want to hear about, ‘Oh, this history and that history,’ because I just want to be able to do the best that I can.

“I want to be able to win and I don’t want any distractions. That’s how I’m going to handle it.”

On the sideline, her coach and confidant, Patrick Mouratoglou, is trying to neutralize the pressure, telling ESPN’s Brad Gilbert that Williams should give herself a break and embrace the feat, he said, that “is just a matter of time.”

“[Serena] shouldn’t be so stressed out. … If we put too much pressure on, we’re just going to fail,” Mouratoglou said.

Feat for the ages

What so many marvel about in regard to what Williams is doing is, ironically, the same thing we admired about Graf — her age.

But ESPN analyst Mary Joe Fernandez, who competed against Graf from the time the two were grade-school age, said that mentally, it’s considerably harder on Serena.

“When you’re younger, you feel like you have more time; ‘If it doesn’t happen now, I’ll get another shot,’ ” Ferenandez said. “I’m sure Serena feels, ‘This is it.’ ”

Fernandez and others often rightfully emphasize that what Williams is attempting to accomplish in the same month she will turn 34 is “simply amazing,” and all the more amazing because she has not breezed through this year like Graf did in ’88.

In the four Grand Slam tournaments alone, Graf won 14 sets at love and 17 at 6-1, compared with four and three, respectively, for Williams in three Slams.

In addition, Graf dropped just one first set while Williams already has lost nine, including five at the French Open alone.

The ability to pull out of those holes has been coined “pulling a Serena” by none other than Williams herself, a phenomenon that has overshadowed the fact that she struggled in the first place.

“I like to be in that zone,” she said of the moments when she seemingly flips the switch and coasts to victory.

But Williams was at a loss to explain a rash of double faults in Toronto, outside of lingering elbow problems, simply saying, “I put too much pressure on myself.”

ESPN analyst Patrick McEnroe, who compares Williams’ pursuit to baseball players chasing Joe DiMaggio’s 56-game hitting streak, reminds us that the pressure is justifiable.

“It’s not like she’s winning 6-2, 6-2 every match,” he said. “There is the benefit of playing two out of three [sets], but there’s also a little bit more pressure in two-of-three where if you do lose a set, the match could be over.”

At 19, it is easy to think that Graf might have been oblivious to the magnitude of her achievement, which was capped by an Olympic gold medal in Seoul less than a month after the US Open. But in an interview with France’s L’Equipe newspaper in June, it sounded more like she was unequipped in many ways to deal with it.

“I remember, above all, the extreme fatigue I felt in New York,” she said. “I was feeling the expectation around me that wasn’t mine. That was suffocating and stopped me [from] concentrating.

“Everyone was talking about this chance and I couldn’t understand it. I was 19. I was just relieved when it was finished, and 27 years [later], I find it unbelievable to have been able to resist the pressure of the Golden Slam.”

Graf, who turned 19 in June of ’88, was just 17 when she won her first major at the ’87 French Open.

At that point, she had not yet advanced past the fourth round of Wimbledon and the Australian Open or the semifinals of the US Open.

The word “potential” was still being used to describe her, and Martina Navratilova was still the No. 1-ranked player in the world. And even after Graf took over the top ranking in September of ’87, Navratilova argued that despite Graf’s 61-2 match record, her victories over the German player in the finals of Wimbledon and the US Open logically should have qualified her as No. 1.

A year later, however, no one was disputing Graf’s place atop the game. And Navratilova, after losing a 6-1 third set to Graf in the ’88 Wimbledon final, snapping a streak of six consecutive Wimbledon titles, graciously called Graf “the better player.”

“This is how it should have happened,” Navratilova said. “If you have to lose, you might as well lose to the better player on the final day and pass the torch, if you can call it that.”

A Grand presence

By the time 1988 rolled around, Graf had developed an on-court presence that could now be compared to any intimidation factor Williams has enjoyed.

“She was such a tremendous athlete that I felt overwhelmed during the five-minute warm-up,” said Fernandez, who was ranked as high as No. 4 in the world and reached Grand Slam finals in singles three times while winning two doubles titles. “It was just another level. We’re in hyper-speed now. She took warm-ups like we were in the match already, so it was not like you could get grooved, and you already felt her pressure and pace and how early she took the ball.”

Perhaps the most remarkable thing about Williams’ year, Fernandez said, is that unlike Graf, who consistently mowed down her opponents, Serena has not played her best for a while.

“I’m still waiting to see [Serena] take it to another level that we really haven’t seen at the majors,” Fernandez said. “She had a couple matches at the Australian against [Dominika] Cibulkova and Maria [Sharapova], the French maybe against Sara Erraniand at Wimbledon the way she started against Venus. But we haven’t quite seen her at her best since the [2012] Olympics, when she cruised and demolished everyone.”

At that point, Williams wondered aloud what more she had to accomplish. But after last year, when she exited in the fourth, second and third rounds, in order, of the first three Slams of the year, Williams has been toughened up by those experiences, Fernandez said.

“I think she’s learned from that, and her team has prepared her for what she is going through now,” Fernandez said. “For Serena, it’s hard because she knows she’s better than everybody but she has had to come to the realization that a win is a win and she doesn’t have to beat everyone 6-1, 6-2.

“Patrick has been a good influence in saying, ‘It’s OK, you’re not always going to be perfect.’ ”

Still, Williams seems hyperaware that she often brings out the best in her opponents, and mentioned it after losing to Belinda Bencic in the semis in Toronto.

“Everyone I play, they play [against] me like if they don’t win, they don’t get to go home and something [will] happen to them. So I don’t know what that’s about,” Williams weakly joked. “But every match I play, they’re going incredibly hard and they’re playing really well, so that’s confidence for me.”

The common belief is that Williams’ toughest opponent is herself, her own errors often the only things that can stop her. And indeed, watching her self-destruct as she did in Toronto, appearing near tears as she looked to Mouratoglou in the stands, can be as compelling as watching her pull a Serena to recover.

Williams is as aware — as are we — of that trap, joking about it later.

“It’s all up to me,” she said. “If I decide to play right, it’ll be great. If I decide to be ‘Baby Rena,’ then …

“I saw someone write that on Instagram. I kind of liked it, though. They were calling me out but I was like, ‘They’re right …’ Hopefully, Baby Rena won’t come out [at the Open].”

If she does, seven-time Grand Slam champion John McEnroe isn’t likely to be ripping her from the ESPN booth. McEnroe said the emphasis on the Slam and the expectations are unreasonable.

“She’s a human being,” he said. “I saw her [Monday] at a Nike event and she’s excited but she’s ready for it to be over with, too. She’s been walking around with this ever since she won the French … so it’s been months and months and months. …”

Like Williams, Graf played sparingly between Wimbledon and the US Open — an exhibition in Tokyo and a clay-court tournament in Hamburg, Germany. She limited her schedule in part because of a dog bite by one of her beloved pets, but also to alleviate the stress of the moment.

“You always need time to get away, to do something different,” Graf said before the ’88 Open. “It was a lot of pressure. Not pressure on court, but there were things outside tennis and after Wimbledon. There were a lot of interviews and a lot of other things and you really feel like getting away from all the people.

“Playing tennis and everything is much easier than what’s all around it. Like in Germany, my matches didn’t last as long as I [spent] giving autographs or interviews after.”

Feel the love?

Adding to the strain for Graf was that she couldn’t win for winning, drawing criticism for dispatching opponents too quickly. So conscious was she of the complaints that she admitted before the Open that it bothered her to the point of considering changing her game.

“It did cross my mind, like when I was in Berlin in May and winning very easily and playing very, very fast,” Graf said. “At the end of a match, I always try to do different shots or play a long rally or come in. I’ve lost a few games doing that and nobody was very happy about it.

“Then in Paris, I was beating Natasha Zvereva 6-0, 6-0 [in the final], and they were saying, ‘Why didn’t you give her a game?’ Again, what the hell? What can you do? Now I’m just playing as well as I can.”

Though ESPN analyst and former pro Pam Shriver recalled Graf as “a shy champion” who rarely waved or engaged the crowd and mostly kept to herself in the locker room, Williams is anything but retiring and often expresses her gratitude for spectator support.

“I don’t always have a tremendous amount of support in the crowd,” she said after defeating Simona Halep in the Cincinnati final. “But I really felt it and loved it and appreciated it.”

Graf rarely was the favorite in U.S. tournaments, even when playing another foreign player and particularly when that player was Sabatini.

In a semifinal loss to Sabatini in the semifinals of the Bausch & Lomb Championships in April of ’88, Graf called the crowd’s treatment of her “very annoying.”

“Some are yelling, ‘Miss it.’ Others are yelling, ‘Hit it.’ I didn’t know what to do,” said Graf, who likewise was not the crowd favorite against Sabatini in the US Open final.

Going into this year’s Open, Shriver said she hopes the New York crowd will demonstrate its allegiance to Serena.

“Given how little Serena has enjoyed the crowd’s support throughout the world, I hope she gets and feels some of the great receptions of all time in our sport because what she is doing at 34, 13 years past holding all four concurrently [but not in the calendar year], being this good with this longevity is truly incredible,” Shriver said.

Mouratoglou made crowd support sound vital.

“It will not be an easy moment because everyone is going to expect a lot from her and put a lot of pressure on her,” he said. “I sincerely hope that the American crowd will help her by giving her incredible support. She is representing the country in the best possible way.

“We will prepare [by] being aware of what is important or not, with putting events in perspective.”

And that perspective, he said, is not to emphasize the elephant in the room.

“I do not want to put too much attention on the calendar Slam,” he said. “Serena doesn’t need it to show how great she is. It is just a bonus and we have to see it that way.”

Williams is listening to the advice. But asked recently if winning consistently creates more pressure, she wisely said it’s better than the alternative.

“I decided I prefer to have that pressure than the pressure of not winning,” she said. “Not everyone can handle that pressure, but I’m OK with it.”

And yet like Graf, it might be hard to conjure up much enjoyment at the same time.

“I don’t care if I win, lose or break even,” she said after Cincinnati. “I’m ready to start [the US Open], get it over with and be done and go on to the next event. …”

Two champions

Williams said she has been heartened by the bits of encouragement she has received from the one person who can imagine what she is going through.

Following the Australian Open final, there was this post on Graf’s Facebook page:

Graf also congratulated Williams on her Wimbledon title.

And it is not inconceivable that should Serena complete the Slam, Graf, who has not made many public appearances at WTA events since her retirement in ’99, could congratulate her in person, as Chris Evert and Martina Navratilova did last year on court after Williams tied their mark of 18 career Grand Slam singles titles.

“I really am still like a kid when I see her or I see posts,” Williams said of Graf. “I get super excited. I’m still living the dream. She’s been really supportive, which is so great to see and to feel that support.”

And if she could ask Graf just one question heading into the Open?

“Well,” Williams said, “I would just ask her, ‘What does it feel like?’ Just in case it doesn’t happen.”