Dallas Cowboys linebacker Rolando McClain revived his NFL career last season with the Cowboys, but his Dallas and football future may now again be in doubt.

McClain, on the eve of his first foray into free agency, is facing a four-game fine which could turn into a suspension for a violation of the league's substance abuse policy, according to a report from Adam Schefter and Todd Archer of ESPN.

As Schefter notes, with the league's updated policy on substance abuse, McClain faces a fine for his third failed test - another failed test and he'll be slapped with a four-game suspension.

McClain, the former eighth-overall pick in the 2010 NFL Draft by the Oakland Raiders, seemed to have saved his professional football career last year in Dallas after retiring from the game amid a flurry of legal issues and general transgressions and missing the entirety of the 2013 NFL season.

McClain took over in the middle for the Cowboys after Sean Lee went down with a knee injury and finished the year with 81 tackles, one sack, one forced fumble and two interceptions for a resurgent Dallas defense that played much greater than the sum of its separate parts.

There was talk prior to this latest failed drug test that McClain may not be long for the Cowboys franchise, as Lee's expected return to health coupled with his questionable dependability and rocky past make determining his value very difficult.

"But there's a big 'if' as to McClain," writes Archer in a seperate piece. "I'm not sure how the Cowboys come up with what's the right price on McClain without having him test the market. You don't want to overpay even for a player who had the season McClain had."

McClain, after joining the Cowboys via trade from the Baltimore Ravens last offseason, played under a one-year deal for $700,000.

At 25, he's just entering his prime NFL years and most likely looking to break the bank, whether with Dallas or another NFL franchise.