He can't afford to get into that kind of trouble against France's Jo-Wilfried Tsonga in the quarterfinals. If he does, Tsonga is ready to pounce for a big upset at Court Philippe Chatrier on Tuesday.
It's no secret Federer's body isn't quite as resilient as it once was.
Now in his 32nd year on this planet, Federer is subject to the same gradually diminishing strength, speed and quickness that comes to all of us as we age.
He's struggled with back injuries this past year and took what looked to be an awkward tumble on the red clay at Roland Garros midway through his match against Simon, as reported by Roland Garros on Twitter:
Afterwards, Federer said he wasn't hurt and that his tumble didn't impact him physically (h/t Julien Pretot of Reuters), but his stubborn refusal to blame injuries for his poor play isn't a new thing.
At this point, it's impossible to know if Federer's mid-match fall against Simon will have any impact on this upcoming match against Tsonga, but even a slight injury could spell doom for the one-time French Open champ.
Tsonga put together his best career performance at the French Open last year, making it to the quarterfinals. He lost that match in five sets to Novak Djokovic, who eventually lost to Rafael Nadal in the men's final.
His road to that point in the tournament was difficult, but Tsonga has been simply on fire this year. He's won all four matches in straight sets and comes into the match against Federer as fresh as is possible at this point in the proceedings.
The Frenchman's past history against Federer suggests the tennis icon will need every single bit of strength, agility and grit to win this match.
They've been involved in a couple of epic, five-set matches in Grand Slam events in the past few years—Federer beat Tsonga at the Australian Open this year, but Tsonga beat Federer at Wimbledon in 2011.
Should Federer show any signs of weakness or fail to show up with his A-game against Tsonga on Tuesday, the younger man will certainly triumph.
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