Juan Martin del Potro will wait anxiously on the results of an MRI scan on his wrist before deciding whether he can face Roger Federer in the Shanghai Masters semi-finals.
The Argentinian fell awkwardly during the deciding set of his last-eight meeting with Viktor Troicki on Friday, damaging his left wrist.
Del Potro received lengthy treatment to the area - which has undergone surgery in the past - before battling through 4-6 6-1 6-4.
Federer subsequently eased past Richard Gasquet in straight sets to book a last-four clash, but it remains to be seen whether Del Potro will be fit to face the Swiss on Saturday.
"I'm glad to reach the semi-finals in this tournament, but to be honest now, as I say always, health is the first of all of my life," Del Potro said.
"I have been dealing with all my injuries in the past, and now it's time to take care of my body, see what the MRI says or what the doctor says.
"But if nothing dangerous happened, I will be here to play tomorrow and doing my best."