Michael Vick has taken another hit — and this one could cost him nearly $20 million.

Already facing prison time, the disgraced quarterback lost the first round in his financial battle with the Atlanta Falcons when an arbitrator ruled Tuesday that Vick should repay much of the bonus money he got while secretly bankrolling a gruesome dogfighting ring.

The case is far from over. The players’ union said it will appeal the ruling by Stephen B. Burbank, a University of Pennsylvania law professor and special master who oversaw last week’s arbitration hearing in Philadelphia.

The Falcons argued that Vick, who pleaded guilty to federal charges for his role in the long-running operation, knew he was in violation of the contract when he signed a 10-year, $130 million deal in December 2004.

The team said he used proceeds from the contract to fund his illicit activities and sought the repayment of $19,970,000 in bonuses he was paid over the last three years.

Any money the Falcons recover from Vick would be credited to its future salary cap, a huge step in recovering from the loss of the team’s franchise player. Atlanta (1-4) is off to a dismal start with Joey Harrington at quarterback.

"We are certainly pleased with today’s ruling," the Falcons said in a statement. "It is the first step in a process that our club has undertaken in an attempt to recoup significant salary cap space that will allow us to continue to build our football team today and in future years."

In a highly technical, nine-page ruling, Burbank said the Falcons were entitled to $3.75 million of the $7.5 million bonus that Vick was paid after signing the deal in 2004, $13.5 million of the $22.5 million in roster, reporting and playing bonuses he was paid in 2005 and 2006, and $2.72 million of the $7 million roster, reporting and playing bonus that he received this year.

Burbank took a different tact than his ruling last year in a bonus dispute involving former Denver Broncos receiver Ashley Lelie.

In that case, the arbitrator ordered the Broncos to repay $220,000 to Lelie, who reportedly had to give up about $1 million in fines, lost bonuses and a prorated portion of his signing bonus to get out of the final year of his Denver contract after a dispute over playing time.

"We have reviewed the decision handed down by Special Master Stephen Burbank and believe it is incorrect," the NFLPA said in a statement. "We will now appeal his ruling."

The case goes to U.S. District Court Judge David Doty in Minneapolis, who still has jurisdiction over the antitrust suit filed by players following the 1987 strike.

Giving teams more financial leeway than he did in the Lelie case, Burbank said Falcons were entitled to recover bonuses for future services that Vick won’t be able to earn because of his dogfighting admission. He was suspended indefinitely without pay by the NFL, in addition to losing millions in lucrative endorsement deals.

If upheld, the decision would be a further strain on Vick’s finances.

He already has been sued by an Indiana bank that claims he failed to repay at least $2 million in loans for a car rental business, and by a Canadian bank that claims he owes more than $2.3 million for real estate investments.

Of course, Vick has more troubling issues to deal with than cash-flow problems. He’ll be sentenced Dec. 10 in the federal dogfighting case and is expected to get at least a year in prison. He’s also facing felony dogfighting charges in Virginia, which carry possible sentences of up to five years each.

In addition, Vick tested positive for marijuana last month, drawing the ire of the judge who will be sentencing him in December. U.S. District Judge Henry Hudson ordered Vick confined to his Virginia home between 10 p.m. and 6 a.m. with electronic monitoring. He also must submit to random drug testing.

Vick’s stunning downfall began in late April when authorities conducting a drug investigation of Vick’s cousin raided property that Vick owns in Surry County, Va. Officers seized dozens of dogs, most of them pit bulls, and equipment associated with dogfighting.

Vick initially denied any knowledge of the enterprise, then pledged after he was charged that he would fight to clear his name.

After his three co-defendants pleaded guilty, Vick followed suit in late August and admitted to bankrolling the enterprise and participating in the killing of eight dogs that performed poorly. In his only public comment since the admission, Vick took responsibility for his actions and asked for forgiveness.

"I offer my deepest apologies to everybody out there in the world who was affected by this whole situation," he said, "and if I’m more disappointed with myself than anything it’s because of all the young people, young kids that I let down, who look at Michael Vick as a role model."