The world No. 6 resumes his season at the Rolex Shanghai Masters, aiming to qualify for the Nitto ATP Finals for the first time.

Even with the biggest shot on the court, the American struggled with the crafty Frenchman before succumbing to a shoulder injury.

The former retired with a shoulder injury after four sets with Adrian Mannarino; the latter lost to Jan-Lennard Struff in straights.