LONDON — American tennis player Wayne Odesnik has accepted "a voluntary provisional suspension" from all events after pleading guilty last month to importing human growth hormone into Australia.

The International Tennis Federation said in a statement Monday that the suspension, which covers Grand Slam tournaments and ATP-sanctioned competitions, started last Friday. Because it is a voluntary suspension, the 111th-ranked Odesnik could decide to play again at any time.

Odesnik has not tested positive for a banned substance. He will face an independent tribunal in the next two months, according to ITF rules, and could be banned for two years.

"How long that suspension will remain in place will be at the discretion of the player, but we would normally expect it to continue through to the point at which a tribunal renders a decision on the case," said Stuart Miller, the head of the ITF's anti-doping program. "Technically, the length of any withdrawal is his choice."

The 24-year-old Odesnik was stopped by customs officers on Jan. 2 when he arrived in Australia ahead of the Brisbane International, a warmup for the year's first Grand Slam event. Eight vials, each containing 6 milligrams of the performance-enhancing substance, were found in his baggage.

He was fined more than $7,000.

"Wayne Odesnik has accepted a voluntary provisional suspension from all events covered under the Tennis Anti-Doping Program," the ITF said in a statement. "In accordance with normal policy, the ITF does not intend to make further comment on this matter until its resolution."

Odesnik has denied taking the banned substance, and despite his plea and subsequent fine, continued to play on the ATP tour. He reached the semifinals of the U.S. Men's Clay Court Championships this month.

Several players have criticized the ATP for allowing Odesnik to compete.

By agreeing to a voluntary suspension, Odesnik will be able to accumulate credit against any suspension brought down by a tribunal. But he must not play in any ATP or ITF events.

"If he decides to return to competition in advance of the decision that is imposed in this case, then he would lose that credit," Miller said.

On Thursday, the ITF said it would review the rules that had prevented it from suspending Odesnik.

Under current rules, the governing body of tennis can only provisionally suspend players who are being investigated for a failed doping test. But players cannot be prevented from playing while they are investigated for other suspected doping violations, such as possessing a banned substance.

Odesnik was born in South Africa and moved to the United States as a child. He turned pro in 2004 and has a 35-43 career record in tour-level matches. He has never won an ATP title and his best ranking was 77th. He has reached one ATP final, on clay in Houston last year, and the highlight of his Grand Slam career was reaching the third round at the French Open in 2008.

Odesnik spends part of the year training in Miami. He is coached there by former top-10 player Guillermo Canas of Argentina, who served a 15-month ban in 2005-06 after failing a doping test.