The defending champion took a medical time-out during the first set of his encounter with Juan Martin Del Potro yesterday, complaining that he “felt something crush in the back of the foot”. After the match, he revealed that the issue almost caused him to pull out.
He will undergo a scan today to assess the damage and discover whether or not he can continue in the competition.
“I’m going to do the MRI. We’ll see what’s going on. I cannot predict the future,” he said.
"I am checking with the doctors, with the physios. They are trying. We are trying to do our best as fast as possible.
"Let's see what's going on and let's see how the MRI looks. And after, let's see if we have the chance to recover for Wednesday. I don't know."
The top seed is next scheduled to face American Mardy Fish.