WIMBLEDON, England -- Nathalie Tauziat renewed her call Monday for a crackdown on drugs in tennis.

Tauziat, 33, of France, said doping was an increasing problem in the sport, although she did not identify any individuals or offer proof of her stand.

"I have no hard evidence, but all I will say is that you don't have to have a degree in medicine to see that some of the players have transformed themselves almost overnight," said Tauziat, who is retiring after this season and is seeded ninth at her final Wimbledon.

"It's time people stopped taking us for a bunch of fools," she said. "I don't care how much training or gym work you do, there is no way anyone can suddenly become stronger and faster in the space of a couple of months."

Tauziat repeatedly has called on the WTA Tour to introduce random drug testing at every tournament and also called for bloodtesting.

Tour vice president Chris De Maria defended the organization's testing policy and said Tauziat would clarify her thoughts Tuesday after her first-round match. De Maria said the WTA tests randomly, but only at some unannounced events. It also has random testing at all four Grand Slams.

"We have a very comprehensive and proven doping program that mirrors the IOC's (International Olympic Committee) and we're very confident in the results we get from that," De Maria said.