Roger Federer called for more drug tests in tennis on Thursday, claiming players are not tested enough and that he had no sympathy for the banned Viktor Troicki.
The Swiss took time on Thursday to reflect on the fall-out from the 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.
"Also last year when I won Dubai, Rotterdam and Indian Wells, and the year before that, I didn't get tested in one of those three events that I won. For me, that's not okay.
"You show up and test a guy that's winning everything. That's sometimes what I struggle with."
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 unwell 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".
"I do believe that when you are requested for a sample, you have to give the sample. It doesn't matter how bad you feel. I'm sorry," Federer said.
"Like the test the next day for me is not a test any more because of what could have happened overnight.
"I believe whatever they decided on. I think it's just very important to give the sample when you're requested to give it because there you are in front of them and there is no way to escape. That's where we just need to be extremely firm."
Tennis has been criticised in the past for an anti-doping programme perceived as overly lax but efforts are being made to make it more rigorous and the ITF announced in March that the biological passport would be introduced.
In 2012, a total of 2,185 tests were carried out, marginally up from 2,150 the previous year, but only 187 of those were blood tests.
The data shows Federer was tested between five and nine times last season, as he was in 2011, while in 2010 he was tested at least eight times.
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."