Michael Vick should be allowed to keep nearly $20 million in bonus money even though his NFL career is on hold because of his role in a dogfighting operation, a lawyer for the players' union argued Friday. The NFL Players Association asked a federal judge to overturn a special master's decision that Vick should forfeit the bonus money because of his guilty plea. The former Atlanta Falcons' star faces up to five years in prison when he is sentenced Dec. 10. Dogfighting wasn't the issue at Friday's hearing. Instead, the arguments turned on interpretations of the NFL collective bargaining agreement. Union attorney Jeffrey Kessler argued that Vick's "roster bonus" should be treated the same as a "performance bonus," which can't be forfeited under the collective bargaining agreement. "A roster bonus is a performance bonus," Kessler said, explaining that Vick earned it simply by being on the Falcons' roster in 2005 and 2006 and that the money a player earns can't be taken back under the contract.