"I think Roger Federer himself, deep down, doesn't know" - Paul-Henri Mathieu on the unpredictability of the Swiss' comeback

Paul-Henri Mathieu believes Roger Federer's comeback after an 11-month layoff will be unpredictable, and that the Swiss himself probably doesn't know what to expect when he returns.

The 39-year-old Roger Federer hasn't played since the Australian Open in January. He underwent two knee surgeries - one in February and another in August - which ruled him out of the rest of the season.

Federer has resumed on-court training now though, and he intends to return to the tour in January 2021.

Back to work😃🏋️‍♂️👨🏼‍🏫📚🍂🍁🎾 pic.twitter.com/zwljm17Rkv

— Roger Federer (@rogerfederer) November 6, 2020

Roger Federer had made a comeback in similar circumstances back in 2017, and he won the Australian Open right off the bat. But this time he is a few years older, and his layoff has been a little longer.

Mathieu explained that given his age, Federer will only be able to assess his chances of returning to the top after he actually starts playing.

"Honestly for Roger Federer, I find it hard to believe that is an advantage," Mathieu said. "We don't know how he will recover. In all fairness, I think he himself, deep down, doesn't know. When you stop for a long time, especially at that age, you don't know how you're going to feel when you go back to it."

The Frenchman, who never defeated Federer in seven career meetings, believes that coming back after such a long layoff will be complicated for the 20-time Grand Slam champion - even with his aggressive style of play.

"Even though Roger Federer has a style of play whereby he can shorten exchanges, over the duration of an entire tournament, in 5 sets, it seems super complicated," Mathieu added.

The uncertainty around the Australian Open schedule coupled with the prospect of playing in empty stadiums may be other challenges for the Swiss in his comeback.

The best-of-five sets format gives Rafael Nadal an advantage, especially on clay: Paul-Henri Mathieu

Rafael Nadal at the 2020 French Open

Paul Henri-Mathieu also believes that the best-of-five sets format continues to remain a big advantage for Rafael Nadal, especially on clay. The Frenchman pointed out that the Spaniard's physical strength makes it easier for him to outlast his opponents in longer matches.

Nadal has won the French Open a record 13 times, and he proved his clay court superiority once again at this year's event.

"For Rafa on clay, this 5-set format is still an advantage. He is the one who masters the game so much that he tires less than his opponent. And that leaves him a greater margin of error than on a Best of three sets. He can lose a set and make up for it. The longer the match, the greater his margin," Mathieu stated.