Stuart Miller, who oversees the ITF’s anti-doping program, tells USA Today that pro tennis players may soon be asked to carry biological passport cards. They are said to be a method of collecting and comparing biological data from athletes so that variances from their normal biological levels can be detected. The variances help authorities detect dopers.

“Our aim would be to implement it, but implementation is reasonably complex,” said Miller, who added that it’s possible that the program could begin in 2014.  
Some players and analysts have called for more blood testing, which is said to be more accurate than urine testing. Doing so would cost more money, however, which means that tournaments and the tours would have to kick in more capital. Miller did agree that cost is an issue.  
Former French Davis Cup captain Guy Forget told the newspaper says he’s in favor of it.  
“Some sports like cycling are more exposed, but we know in our sport some players have been caught,” Forget said. “It would be foolish to not be concerned by these problems especially since the game got more physical.”