Vikings center Matt Birk, the last remaining link to the team’s 15-1 season of 1998, has decided not to participate in voluntary offseason workouts.

Birk is entering the final year of his contract, and the team has made no effort to extend the deal.  Thus, it’s likely that Birk will hit the free-agent market in March 2009.

In 2008, he’s due to earn $5.32 million in base salary and a $400,000 roster bonus.

“I don’t feel like I need to plead my case for a contract,” Birk told the Minneapolis Star Tribune.  “I think my career and my 10 years in this league speak for themselves.” 

The other reality Birk faces is that the Vikings might decide to approach him in August with a “take a pay cut or take a hike” ultimatum. 

Then again, if Birk were to call the team’s bluff, the Vikes would be S.O.L. at the center position in 2008.  Unless, of course, they draft Birk’s successor and decide to install him as the starter.