Roger Federer called for more drug tests in tennis on Thursday, claiming players are not tested enough.
The Swiss took time on Thursday to reflect on the fall-out from the Viktor Troicki affair after beating Richard Gasquet 6-4, 6-3 to keep alive his hopes of reaching the semi-finals of the ATP World Tour Finals.
"I just feel like we're not getting maybe tested enough," said the six-time year-end champion.
"I didn't get tested in Basel, in Paris (October). I got tested here after the first match.
"I feel there needs to be more testing done. I feel like I used to get tested more, I think I was tested 25 times in 2003, 2004. Ever since, I think it's been clearly going down this season."
Federer spoke after outrage from world number two Novak Djokovic over the ban handed to his fellow Serb Troicki for skipping a blood test after feeling poorly and coming back to do it the next day in Monte Carlo.
It was a transgression which originally cost him an 18-month suspension before it was cut to 12 months earlier this week.
Croatian Marin Cilic last month completed three months out of the game for accidentally ingesting a banned substance through glucose tablets.
While Djokovic said he no longer trusts the anti-doping system, Federer took the opposite approach, along with Andy Murray, out injured from the year-end event, who tweeted: "Read and respect the rules and everything is very simple."
Federer added: "Overall I trust the system. I think they're all very professional. I just think it's very important that they treat us like normal human beings, not criminals.
"It's fine to treat a guy bad if the guy tested positive, the guy needs to feel the pain, but not if you haven't done anything yet. That, to me, seems like that's the case. So I appreciate that."