Because there is a lockout right now, free agency has not happened yet. It's entirely possible the NFL Draft could take place first, which would make for a very interesting dynamic this offseason. Teams could be forced to draft players and fill the rest of their needs via free agency rather than vice versa.
A great deal of things, including when free agency begins, will depend on the NFLPA's preliminary hearing on April 6, as they want to be able to stop the lockout. If successful, free agency could get started just weeks before the draft. While it would be about a month later than usual, it would give teams plenty of time to sign free agents and re-sign their own players before the draft. If nothing happens quickly with the ruling (i.e. there are many appeals), however, free agency could be destined for after the draft.
"It's been business as usual with our free agency (preparation). Most of those discussions have already occurred," Schwartz said. "We still don't know what the parameters are going to be, but that doesn't stop the evaluation -- evaluation of players is a 24/7/365 proposition. It doesn't change because of timetables and dates and things like that. So, we were ready regardless of what happened."
By this point, the Lions probably already have specific guys in mind to target in free agency. I'm sure they have planned for not being able to sign anyone until after the draft as well, which would put a premium on signing guy to fill needs that they are unable to address during the draft. This dynamic definitely will alter teams' strategy, but it sounds like the Lions have already planned for the possible change.