LONDON -- Tennis' biggest names have urged the tennis authorities to protect the sport's clean image by making drug testing more transparent.
Roger Federer, Rafael Nadal and Andy Murray, speaking at pre-ATP World Tour Finals press conferences in London on Friday, claimed that more anti-doping resources were needed for tennis to reduce the chances of a scandal similar to the one rocking athletics.
An independent commission set up by the World Anti-Doping Agency has accused Russia of a "state-sponsored doping programme" and of "sabotaging" the 2012 London Olympics, and Federer suggested his sport should increase both in-competition and out-of-competition testing.
"They are trying their most but we can do more," said Federer, who faces Tomas Berdych on Sunday, on the season-ending tournament's opening day. "Whenever you make the quarterfinals of a tournament, when the points are greater, the money is greater, you should know that you will be tested.
"That would be very clear and simple. And if they keep the tests for longer, I'm all for that, not just weeks and months, years I'm talking about. That's the way to scare people.
"There needs to be more resources. It's very important. Players need to feel that they're going to be tested, so they will shy away from any stupid thought they might have.
"I'm always surprised when I walk off court after a final and I'm like 'where is anti-doping?'"
Fourteen-time Grand Slam winner Nadal insisted the authorities rather than the players should foot the bill for increased testing, but would give up winnings if necessary.
"Without being arrogant, it's a rich sport, we have a very healthy sport, the people who run the sport need to be sure sport is clean," he said.
"Players need to be sure and confident with people who run the sport to be 100 percent clean in the right way. I don't care if we have to put prize money, fine for me.
"[It] will be great if one day the anti-doping that we do is 100 percent public."
According to the International Tennis Federation -- which manages, administers and enforces the Tennis Anti-Doping Programme on behalf of the ATP and the WTA -- more than 2,000 doping tests were conducted in 2011.
Those tests were "both in-competition and out-of-competition, and included both urine and blood samples".
The ITF website states: "An out-of-competition testing programme has been conducted under the Tennis Anti-Doping Programme since 2005. This programme has been fully WADA Code-compliant since out-of-competition testing became mandatory in 2009.
"Players subject to this programme provide daily whereabouts information in order to permit effective no-notice out-of-competition testing."
However, British No.1 Murray warned that more testing did not always result in a clean sport. He said: "I think the more transparency the better, there's absolutely no question about that.
"We, as a sport, could invest more money in anti-doping processes. Prize money now is so high, there's no reason not to have as perfect a process as possible.
"This year I've been tested more than ever before, the most in my career this year. But it's getting to the stage where that doesn't matter anymore.
"I've been tested more than any athlete but it doesn't make a difference. Lance Armstrong was the most tested athlete on earth and didn't fail a drug test. That doesn't necessarily guarantee anything."