The Swiss former world number one, making her WTA summer hardcourt start in San Diego this week, complained that a Sunday drug test during a pre-tournament training day threw off her carefully prepared routine for no good reason.

Hingis, who returned in January after a long break from the sport, said drug testers need to have some consideration.

"They should look at a player's schedule. They just come in and screw up your whole day," the five-time Grand Slam winner said Monday.

"They could come at the end of the day or in the morning, but not in the middle of the day when you have training scheduled.

"It's not a big difference if it's in the morning, the night or the next day. It's not like anything's going to go away."

Doping tests are a timely topic across all of sport these days given the latest doping allegations against two US stars, Tour de France winner Floyd Landis and 100m world record co-holder Justin Gatlin.

Hingis said she is all for random drug testing - "the rules should be respected," she declared - but that testers could do with some consideration for those who take the tests.

Hingis said she will never forget a 6 a.m. test performed in Switzerland in 1996.