Second drug test comes back clean for NFL safety Tom Zbikowski

• Reprints

Updated: August 4, 2011 4:20PM

Former Notre Dame and current Baltimore Ravens safety Tom Zbikowski was among five fighters suspended for failing a drug test after participating in Saturday’s boxing card at the WinStar Casino in Thackerville, Oklahoma, the Chicago Sun-Times has learned.

The Chickasaw Nation Boxing Commission tested fighters before the fights and had suspended those testing positive for 45 days pending a second negative drug test. Zbikowski submitted to a more comprehensive and independent test Tuesday in Chicago, and those results came back negative, the Sun-Times has confirmed.

Zbikowski’s original test was positive for marijuana.

“The test administered in Oklahoma before the fight was not as comprehensive as those required by other state commissions,” a source told the paper.

Zbikowski’s manager, Chicago-area lawyer and boxing coach Mike Joyce, was confident there had been a mistake.

“It was disappointing and disheartending because we had such a great experience down there,” Joyce said after the re-test, “but we’re confident we will get this resolved this week.”

Zbikowski, a former Buffalo Grove football star and long-time successful amateur boxer, improved his professional record to 4-0 with a first-round knockout of Blake Warner on Saturday night.

“He’s taken all sorts of tests for the NFL and he’s never tested positive ... ever,” Joyce said.