Alexander Zverev is unsure whether his hamstring injury will affect his grass-court schedule.
The 21-year-old German seemed to experience the injury during his quarterfinal against Dominic Thiem at the French Open, having played three five-setters coming into the encounter. Zverev, who fell in three sets in his first Grand Slam quarterfinal, could not assess the extent of the problem.
Match point from Zverev's loss to Dominic Thiem in the French Open quarterfinals: