The Detroit Lions still have work to do before the start of free agency on March 12.

Even after releasing veterans Kyle Vanden Bosch and Stephen Peterman, and restructuring the contracts of Nate Burleson and Dominic Raiola, the Lions need to clear additional cap space if they want to retain some of their key free agents or hope to pursue any players on the open market.

The primary short-term solution would be extending the contract of Matthew Stafford, lowering the quarterback's $20.8 million cap number for 2013 in the process. But it's not a given the team will be able to get that done.

Lions general manager Martin Mayhew has begun conversations with Stafford's agent, but there's no assurance the sides will be able to reach an agreement in the next few weeks.

Mayhew told local beat writers on Friday the team is prepared for either scenario.