UPDATE: Christopher Clarey of the New York Times reports that John Isner suffered a stress fracture in his left foot, and is expected to miss 4 to 6 weeks.

Word from John Isner camp is that it appears he did suffer a stress fracture in his left foot during Miami Open final against Federer. More definitive test results forthcoming but could miss 4 to 6 weeks. If so, quite a pity for a big man back in excellent form (6th in the race) — Christopher Clarey (@christophclarey) April 2, 2019

John Isner is unsure about the condition of his foot following an injury in the Miami final.



The 33-year-old began having visible problems during the second set of his defeat to Roger Federer, calling the trainer and telling his box, "I can't move."



When he got off the court, Isner said he did not know what the injury was and had not had anything similar.



"No, I have never had anything like this before, ever," he told press at Miami. "I have been very fortunate. I have stayed healthy throughout my career. Something happened today.



"In the first five games, I was fine. Nothing was bothering me. Then, you know, this weird pain on the top of my foot, we'll see what is."





The No. 9 said the problem grew during the contest, though he was more competitive in the second set than the first set. By 5-4 in the second, he was hobbling on the court.



"It wasn't like a certain point, either. I just started feeling something, and it just kept getting a little worse, getting worse and worse as the match went on," he said.



Though saying Federer had been "too good" regardless of the injury, Isner indicated he had been havign significant pain and was concerned.



"I mean, I have never had a broken foot, but that's what I would imagine it would feel like," he said.



Isner is next scheduled to play the ATP clay-court event at Houston, but appears to be in some doubt for the competition.