The signings aren't really anything new, as we had previously heard about three of them: DE Cliff Avril, LB Bobby Carpenter and CB Chris Houston. Avril signed his one-year tender on Thursday, and Carpenter inked a one-year deal of his own. Houston signed a deal for two years.
The fourth player who signed on Thursday is offensive tackle Isaac Sowells, who previously played for the Bengals and in the UFL. He worked out for the Lions on Wednesday.
To make room on the roster for these four players, the Lions released WR Michael Moore, OG Pat Illig, CB Branden Bufford and CB Brandon Stephens. All of these players were originally signed as undrafted free agents. Moore signed last year and spent the 2010 season on the practice squad. The other three had just signed last week.