How Hall of Famer Andre Agassi sees the ATP World Tour Finals

NEW YORK -- Inside the glistening new World Trade Center transportation hub in downtown Manhattan, thousands of commuters and shoppers stream through the slick mall daily. On Tuesday, a tennis legend was part of that scene.

Andre Agassi, the American great and Hall of Famer, was there to host the launch of a new watch at the Longines store, where he took time to speak with ESPN.com about next week's ATP World Tour Finals in London and his continued work as coach to Novak Djokovic, a relationship that began this spring.

Djokovic hasn't played since he retired in the Wimbledon quarterfinals in July because of an elbow injury. He took a page out of the playbook of another great -- Roger Federer -- by calling it a year in order to fully recover and is set to return at the start of next season.

"He's done fantastic work in making sure he's over his injury once and for all, which was a fracture in the elbow," Agassi said. "We'll know in a week from now if that's fully behind him, which is great. He's used the time [off tour] to train -- a lot."

Where Djokovic won't be in a week is at London's O2 Arena, where the ATP Finals will be headlined by the two players who owned the 2017 tennis year in shocking throwback form: 36-year-old Federer and 31-year-old Rafael Nadal, who already has clinched year-end No. 1 status.

The tournament's format, with round-robin play in two four-player pools producing the four semifinalists, means that a loss doesn't necessarily result in elimination. The field consists of Nadal, Dominic Thiem, Grigor Dimitrov and David Goffin in Group Pete Sampras; and Federer, Alexander Zverev, Marin Cilic and Jack Sock in Group Boris Becker. Dimitrov, Goffin, Zverev and Sock are making their debuts in the year-end event.

Agassi answered a handful of questions from ESPN.com on what we can expect starting Sunday in London.

ESPN.com: Andre, 2017 has been all about Roger and Rafa. Are they the favorites to win here?

Agassi: Historically, Rafa's end of the year is never quite the same as the middle or the beginning. A lot of that goes into the wear and tear and the intensity that he brings to the table [each match]. Who knows with Roger. In a lot of ways he wasn't himself at the US Open and leading up to it. He's taken his time and has proven to be a person that makes pretty good decisions. I do expect him to be at his best.

Is this Federer's last ATP Finals? He's said he wants to keep going and going.

Agassi: The one thing I can tell you about the end of someone's career is when it comes, it comes fast. But he's certainly proving that we can't predict when it's coming. Unfortunately, though, at some point we're going to have to say goodbye to someone who has been so great for the game.

No Novak in London, and also no Andy Murray, Stan Wawrinka, Milos Raonic or Kei Nishikori. What do you make of this field? Depleted? Opportunities for new faces?

Agassi: I haven't studied it much, to be honest. My focus has been the big picture moving forward with Novak. Obviously, watching what Alexander Zverev has done this year, he's been pretty spectacular. There are a few guys in there for a first time, so it's hard to predict. Some are going to be nervous and some are going to overachieve. It's a great format for fans. It's a great arena. I'll enjoy watching it -- but I'm out of the prediction business! [Laughs.]

You played the event 13 times, winning it once. But three times you made it out of the group stage with a loss -- including the victory in 1990. What makes this format different, and what do you like about it?

Agassi: It gives you the chance to strike out, right? It also gives you a chance to recover and to set the stage. I love seeing how champions respond to disappointing days. We don't normally get to see that. You see someone lose a big match and then they disappear for a few weeks and come back ready in a whole new environment. It's different when you lose yesterday or the day before, on this very court, and you have to come back and sort of figure out how to believe in yourself again. I think it touches on a few of those elements in a competitor.

Jack Sock was 24th in the race and then wins his first Masters 1000 in Paris last week and finds himself qualified for the Finals. What advice would you have for the first American in London since Mardy Fish in 2011?

Agassi: Let it fly, really. You don't get the luxury of working yourself into this event. You're playing the best of the best and you have to come out and play every point like it's break point and play every match like it's the final. That'll be a great experience for him.