It's franchise tag day -- sort of

Officially, Thursday is the first day NFL teams can place a franchise tag on players whose contracts are expiring and would otherwise be eligible for unrestricted free agency.

But in one of many twists we can expect in the structure of the 2011 offseason, the NFL Players Association has declared the franchise tag to be irrelevant until a new collective bargaining agreement (CBA) is reached.

The existing CBA will expire March 3, and the reality is no players will be changing teams this offseason -- whether they are franchised or not -- until the league reaches a labor resolution.

It is possible, however, that players who are franchised now could be grandfathered into the next CBA. So it's at least worth discussing who might be candidates here in the NFC North. The exact salary levels, as well as the number of years required for unrestricted free agency, are yet to be determined. Below we've included players with at least four years of experience.

Team: Chicago Bears

Prominent players with expiring contracts: Defensive tackle Anthony Adams, tight end Desmond Clark, cornerback Corey Graham, quarterback Caleb Hanie, center Olin Kreutz, safety Danieal Manning, punter Brad Maynard, linebacker Nick Roach and linebacker Pisa Tinoisamoa.

Comment: Kreutz probably doesn't need to be protected with a tag. Hanie could garner interest around the league but would you guarantee him franchise money to stay?

Team: Detroit Lions

Prominent players with expiring contracts: Safety C.C. Brown, cornerback Chris Houston, defensive end Turk McBride and quarterback Drew Stanton.

Comment: Tom Kowalski of Mlive.com reports the Lions won't use the tag.

Team: Green Bay Packers

Prominent players with expiring contracts: Safety Jarrett Bush, left guard Daryn Colledge, running back Brandon Jackson, receiver James Jones, defensive end Cullen Jenkins and running back John Kuhn.

Comment: Jenkins is a possibility, although the Packers have a young player in Mike Neal who might be ready to take over his spot next season. Colledge's status is uncertain.

Team: Minnesota Vikings

Prominent players with expiring contracts: Defensive end Ray Edwards, linebacker Chad Greenway, linebacker Ben Leber, receiver Sidney Rice, defensive end Brian Robison and nose tackle Pat Williams.

Comment: Greenway and Rice are young players the Vikings would hate to part ways with. They have seemed cooler on Edwards' status.