It's easy to look at Roger Federer's match records and conclude that he's one of the best of all time.However, a new statistic tweeted out by 1989 French Open winner Patrick McEnroe reveals an even more incredible level of resilience and passion in the Swiss than we might've ever realised.The tweet reveals that during his professional career, Federer has played a mind-blowing 1,511 matches. In that time, he has failed to complete zero of them.He has never retired mid-match due to injury or discomfort, which is an absolutely insane statistic, which goes to show the determination Federer has to win.While this statistic does show that Federer has managed to maintain an incredible level of fitness throughout his career, this isn't to say that he's never been injured during his playing-time. 

One Twitter user commented that he's never medically retired from a match, even when his back was so bad that he had to sit on the linesman's chair between points in his 2008 ATP Finals match against Andy Murray.

Even still, Federer played on despite the immense discomfort he must've been in.

Another user added: "Djokovic and Nadal are both ultimate professionals, but this stat puts them both to shame. Whether or not he holds the all-time singles Grand Slam record after the three have retired, this stat will prove he is the greatest of all time!"

Some fans saw this stat more as something to worry about rather than to celebrate, with some arguing that it is time for Federer to throw in the towel before the record gets tainted, and others saying that playing through injury is a sign of foolishness, rather than bravery.

Whichever way you take it, this statistic is an amazing achievement which will stick with Federer's already incredible legacy for the rest of time.