It seemed Canadian Milos Raonic was just getting to like playing on grass.

But the 20-year-old ace tumbled during his second-round match Wednesday and was forced to withdraw from Wimbledon.

Raonic was leading Gilles Muller 2-1 in the first set when he slipped at the baseline while trying to make a return. His right leg bent awkwardly and he seemed to injure his thigh.

After a few minutes, Raonic had the leg wrapped by a trainer.

Despite having to limp, Raonic tried to play on but retired up 3-2.

The hard-serving Raonic might have been a force at Wimbledon. Two weeks ago on the grass at Halle, Germany, the Canadian made it to the quarterfinals.

"Well, I'm very happy that I can play here," Raonic said at the time. "Grass is a totally new experience for me and I can use my being here to gain more confidence on the surface. I have already noticed that I get a couple more aces and a couple more unreturned services."