Novak Djokovic, who has reached the final of Montreal, said he is having problems with a chronic arm injury.
The Serb called for the trainer during a straight-sets semifinal win against Jeremy Chardy, saying that the injury was bothering him but is something he has had before.
"It comes and goes," he said in a court-side interview in Montreal. "Right now it's not very pleasant to play with. But it's part of our job."
Djokovic is also playing doubles in Montreal with Janko Tipsarevic, and was pushed to three sets against Ernests Gulbis in the quarterfinals.