Milos Raonic, who has led Canada into its first Davis Cup semi-final, sees no major edge with opponent Serbia losing Viktor Troicki to an 18-month doping ban.

The big-serving Raonic, 13th in the ATP rankings, will lead Canada onto clay courts at Belgrade for the showdown against world number one Novak Djokovic and Serbia.

Troicki won the fifth and deciding match for Serbia over France in the 2010 Davis Cup final.

"Even if he's not playing, there are other matches we have got to win. That doesn't change," Raonic said.

While the upcoming US Open is Raonic's top priority, the Davis Cup opportunity is thrilling to him as well.

"I'm looking forward to it," Raonic said. "It is an exciting week in my schedule."

Troicki's case and a reported doping violation by Croatian Marin Cilic have made doping and the ATP drug testing system a topic at this week's ATP event in Washington.

"Sometimes it can be frustrating. You've just lost a match and they (testers) are asking for your time," Raonic said. "But I don't think there is anything wrong with it."

Germany's Tommy Haas, ranked 12th, said he has no problems with the way players are tested.

"Our sport has been clean for a number of years," Haas said. "You want to make sure this is a clean sport and make sure we're tested as much as possible."