Didn't seem like much of an injury. he didn't call a time-out anyway. just got a brief rub down off the trainer at the end of the 2nd set. seemed to be the thigh area just above the knee. Looked more like fatigue.
And the major yips on the 2nd serve showed how low his confidence is right now. He lost his serve with a df at least 3 times.
He got footfaulted a heap of times too, which wouldn't have helped. Jarkko did too which is something I've rarely if ever seen in a match before.