The San Francisco 49ers' offseason roster tweaking continued Tuesday when the club announced the addition of a new undrafted rookie cornerback. CB Derrick Canteen signed a three-year deal with San Francisco as their seventh UDFA addition after impressing in a tryout at rookie minicamp.

Cooper is a 6-foot-3, 280-pound defensive end who played collegiately at Tulane and then Houston, going undrafted after completing his Cougars career. He primarily played DE for Houston, racking up 3.5 sacks in his final year. He's a crush-the-can style of EDGE that the Lions favor, and that showed in Friday's rookie minicamp session.

Guard Mekhi Butler and defensive tackles Isaiah Iton and Wilfried Pene were added. The Patriots also released undrafted rookie tackle (and Merrimack graduate) Cole Birdow.