Many baseball players are tired of seeing colleagues who are punished for using performance-enhancing drugs (PED), then receive large contracts a short time later, the Los Angeles Times reports. They are calling for tougher sanctions for players who use PEDs.

Last summer, outfielder Melky Cabrera, who was then playing for the San Francisco Giants, was suspended 50 games for testing positive for PEDs. Two months later, he received a two-year, $16 million contract.

Houston Astros’ catcher Jason Castro, the team’s representative to the Major League Baseball (MLB) Players Association, told the newspaper, “Obviously there’s a want [among] the majority of the guys in the game to keep baseball clean. Players are getting very involved. And it’s a good thing to see because it’s our careers and it’s our game and we want a level playing field.”

MLB is investigating allegations that about 20 players used performance-enhancing drugs, including the New York Yankees’ Alex Rodriguez and the Milwaukee Brewers’ Ryan Braun. Both players deny using performance-enhancing drugs. MLB may seek 100-game suspensions for all of the players, who are expected to fight the move.

The players are connected with a Miami-area clinic, Biogenesis of America, which is now closed. In January, a Florida newspaper reported Rodriguez and Braun obtained performance-enhancing drugs from Biogenesis. MLB filed a suit against Biogenesis for allegedly providing performance-enhancing drugs to players, and advising them on how to pass drug tests. The clinic’s owner, Tony Bosch, reached an agreement to cooperate with a MLB investigation, the article notes.

Under current baseball policy, a player who tests positive for PEDs receives a 50-game ban. A repeat offense brings a 100-game suspension. The newspaper reports 39 major league players have been suspended since the policy went into effect in 2005. The policy does not state what happens when a player returns from a suspension.