PARIS -- Tennis is considering whether to adopt blood-testing measures used by cycling and track to catch drug cheats.
"We are looking very, very carefully at an athlete biological passport program in tennis," International Tennis Federation anti-doping manager Stuart Miller told The Associated Press in a phone interview.
Biological passport programs in cycling and in track and field monitor athletes' blood readings over time for possible tell-tale indications of doping. The federations for those sports, the UCI and the IAAF, have used evidence of doping gathered from these programs to ban athletes and target others for more testing.
Miller said "it would be nice" if tennis can establish such a system in 2013.
"I don't want to say it's definitely happening until we actually say, `Here's a program. It's up and running," Miller said. "We're looking at it to ensure that if we do run it, we can run it properly."
Miller said the ITF also is working toward more of the blood and out-of-competition drug tests it already does on players.
In the wake of cyclist Lance Armstrong's life ban from sports for doping, Roger Federer and Andy Murray called for more out-of-competition and blood testing in tennis.
Murray called the Armstrong case "pretty shocking."
"You would hate for anything like that to happen to your own sport," Murray said before the season-ending ATP finals in London.
Federer said: "We don't do a lot of blood testing during the year. I'm OK having more of that."
The ITF and the World Anti-Doping Agency conducted just 21 out-of-competition blood tests -- used to detect the abuse of growth hormone, transfusions using blood from donors, and blood-doping substances CERA and HBOCs -- in tennis in 2011.
The vast majority of tests in tennis in 2011 -- 2,019 of a total of 2,150 -- were urine.
"We're working hard to try to increase the proportion of out-of-competition testing, and particularly blood testing, and we've been working on that for a while," Miller said. "I'm hopeful that by the end of the year, we'll have made some inroads into improving that.
"Like any anti-doping program, we're subject to resource constraints."
Miller told the AP that the ITF tested Federer an average of eight times per year from 2004-2006, 11 times per year from 2007-2009 and nine times per year in 2010-2012.
Just three of the out-of-competition blood tests in 2011 were on female tennis players. ITF statistics on its web site show it didn't test Serena Williams out of competition at all in 2010 and 2011, years she won the Australian Open and Wimbledon and lost a U.S. Open final.
The ITF did test Williams in-competition at least seven times in 2010 and between 1-3 times in-competition in 2011.
"I get tested a lot," Williams said last month at the WTA Championships in Istanbul, Turkey. "For me, it's a pretty intense system, and I know a lot of the players feel the same way."
The U.S. Anti-Doping Agency's web site shows that before one test in the second quarter of this year, it hadn't organized a test on the 15-time major winner since 2008.
Li Na, the 2011 French Open women's singles winner from China, also was not tested out of competition by the ITF or WADA in 2011 or in 2010, but was tested in-competition.
Of the 642 tested tennis players, 510 were not tested out of competition at all in 2011 -- when athletes aren't playing between events or in the offseason.
Cycling conducted 6,500 more tests than tennis on professional road racers last year and an average of nine tests per rider, compared to an average 3.4 tests per player in tennis.
By way of comparison, Canadian cyclist Ryder Hesjedal, winner of the Giro d'Italia, has had 22 urine tests and 13 blood controls so far this year.
The ITF budget shows it spent $1.3 million on testing in 2011, which Miller said doesn't include salaries and other operating expenses.
That is less than Federer and Williams each pocketed for winning the men and women's singles titles at Wimbledon this year.
Cycling says it spent $4.7 million on testing alone in 2011, with teams, riders, race organizers and the UCI all contributing.