Editor's note: This story was originally published on Aug. 21, 2018.

Other than playing Rafael Nadal on clay, the scariest task in men's tennis is facing Roger Federer pretty much anywhere. No one blends power, touch and creativity like he does, and playing the 37-year-old these days means taking on a living legend. As Federer heads to the U.S. Open looking to add a 21st major win to his record, we asked current and former pros what it's like to be on the other side of the net.

Andre Agassi

8-time Grand Slam champ; 3-8 vs. Federer

"When a ball left my racket [with most opponents], I knew exactly where it was going and I could assess to what degree I would gain the advantage in that point. With Roger, you could not count on the advantage no matter where you hit the ball. He was leaps and bounds better than anyone I had faced. When I faced him late in my career [in the 2005 U.S. Open final], the biggest reaction I got was him looking down at his shoes. Then he just went to a gear I'd never seen before. It was a privilege to see, a privilege to have the worst seat in the house watching it. The truth is, me at my best, him at his best -- I would have had to be perfect to cause him any distress. What I needed to do to display what I was good at, he could neutralize. That turned me into a relatively average player."

1-1 vs. Federer, including an upset win at Wimbledon in 2013

"Over three and a half sets, I was not thinking about winning. I was just going point by point, trying to hold on. Then I was a break up in the fourth, and you start to think, and that's the problem. You become nervous. You go for shots you didn't go for before. You are pressed down by that other Federer, the legend. I was up 6-4 in the [fourth-set] tiebreak and serving, and he passed me. You had a match point on your serve; you may have just missed your opportunity. OK, you're not going to win it -- that is the honest mindset. That backhand that he missed -- I was in disbelief. [Federer shanked a backhand on the next point to give Stakhovsky the match.] At the end of the line, he's also a human being. Not always but sometimes."

World No. 18; 0-4 vs. Federer

"He makes you so uncomfortable. Any ball lands short, he's on top of it so fast. He's into the net, taking time away, angling into balls. He may be 37 now, but his footwork is like a fresh 18-year-old on tour. You're playing a style of play you don't want to play and feeding right into how he wants to play. The next thing you know, you've lost 6-2, 6-2 and are feeling like an idiot. People don't talk about his serve a ton. I don't know if I've ever broken him. I'm pretty crafty on the return games, but I have no idea where [Federer] is serving. It's not coming in fast, 116 to 121 mph, but he's hitting his spot. You feel like if you don't hit a great return, don't neutralize perfectly, you are on the defensive already, and he's holding 98 percent of the time."

A 24-year-old Federer beat Agassi to capture his second U.S. Open in 2005. It was Agassi's last appearance in a Grand Slam final. AP Photo/Amy Sancetta

Childhood friend; 0-2 vs. Federer

"We met when we were 6. From the beginning, we were friends. We practiced together. The first time we played a real match was a tournament series in Switzerland. You play up to nine. I won that one. That was the only time I won. We had funny matches. We were very emotional. We got warned by the supervisors. We were playing on the sixth court, in Bern, so people could only watch on the terrace from Court 1. Imagine how much noise we made that people would complain and send the supervisor to Court 6 to warn us. We were screaming, tossing rackets. It was never against the other. You just got frustrated by your own game, your own mistakes. We walked off the court as we walked on, as best friends."

World No. 33; 0-13 vs. Federer

"Maybe the biggest difference between him and [Novak Djokovic, Rafael Nadal and Andy Murray] is that he takes the first chance. Murray is a great returner, but if you survive the return, he lets you play. If you hit to Rafa's backhand, maybe you get time to play the point. Maybe Djokovic on hard courts is more aggressive than the other two, but Roger is completely different. He doesn't care if he makes 10 mistakes. If you are short, he attacks, he comes to the net, and we all know he does this combination well. It's never great to lose so many times against one opponent, but if I have to pick the best losses [over my career], they're the ones I played well against him. I hope he continues to play a few more years, myself also. It would be great to at least win once."

World No. 8, known as "Baby Fed"; 0-7 vs. Federer

"I remember the first time I played him. It was in Basel [Switzerland]. I thought I played so well. But I never experienced someone who takes time away like that, who has such a clear vision of the game. He's always one step ahead of you. That makes him so dangerous. Sure, he's an icon, but at the same time, we are all even when we are out there. But, of course, you get to tough moments and he's better in many, many ways. Yeah, we have some similarities and I've always appreciated the comparisons, but I think our game plans and how we play are completely different. He's the greatest out there. I hope he keeps playing ... but not too long."

0-3 vs. Federer, including a 5-set loss at the 2017 U.S. Open

"I was ready to go. Let's beat him. Let's do something crazy in New York. Let's get the crowd behind me. I'm a crowd-pleaser myself. I came out playing great tennis. I was serving well. It was an unbelievable match and something I'll remember forever. He stepped up. He's so good at stepping up at the big moments, so good at taking time away from his opponent with his feet. It's like he's playing pingpong out there. He pounces on the ball so quick. He measures the ball so well and creates crazy angles. You can't read his serve. He's the GOAT for a reason."