As the Australian Open champion, Petr Korda, began his title defence after escaping a one-year ban for steroid use, the former world No 1 said he was more concerned about blood doping in the sport than steroids. "I'm much more inclined to have a concern for something that we cannot test for under the current system of testing, which is blood doping," Courier told a news conference.
Blood doping, involving blood transfusions to boost an athlete's crucial red cell count, is usually linked to endurance sports such as cycling and cross-country skiing.
Britain's Greg Rusedski joined in the debate by saying he is prepared to see prize-money reduced so the tennis world can crack down on drug abusers. Rusedski said: "I think tennis should take a stance and make all the players take a blood test three or four times a year. That's the only way you can trace it, and I'd be happy to have the money to fund it taken out of our prize-money."
Courier, 28 and winner of four Grand Slam titles, said he was unable to perform at his peak throughout the year and doubted other players could. "I can't play 35 weeks a year, God knows how many matches, and keep going," he said. "I just can't do it, and I don't think anybody else can either. But they are."
"From what I've deducedthere may be some suspicious things going on that I'm unaware of and that are not being properly sourced out through our testing," he said.
The allegation met with a mixed response among his fellow players. The Austrian baseliner Thomas Muster retorted: "I am 32 years old. I am still playing, and I am not taking drugs, and I am still playing maybe 30 weeks a year, as much as I like. I think we are pretty much on the edge of destroying the sport by making comments like that. If you don't have proof you shouldn't say things like this."
By increasing their haemoglobin levels, blood dopers are able to process more oxygen during their exertions. There are currently no blood tests used to prevent it, although the International Olympic Committee is hoping to introduce one before the Sydney 2000 Games.
"It's clearly prevalent in European sports and most of our tour is in Europe," Courier said. "By deduction - and I'm throwing darts, I have no proof, I can't name names, I wouldn't bother naming names - it just seems a logical way for a player to improve," he said.
Rusedski, meanwhile, is more concerned about high-tech drugs. "I think it would be great if we had blood tests every year, three, four times a year, because the problems are EPO and growth hormone and stuff like that," he said.
Andre Agassi was quick to play down the blood doping debate. "I have absolutely no knowledge of anyone blood-doping whatsoever," said Agassi, who is back in the top 10 after crashing to 122 two years ago.
Courier and Rusedski are the latest players in a long line who have reacted to the Korda case. A number of them are against the lenient treatment he received after testing positive for the steroid nandrolone at Wimbledon last year. The 30-year-old Czech faced a minimum one-year ban for steroid use, but escaped with a fine and loss of points after telling an International Tennis Federation panel that he had not knowingly taken the drug. The ITF is appealing against the panel's decision.
"I don't think anyone here or in the locker-room... will disagree when I say that if you test positive for steroids, you should be out of the game," Courier said.