Locke was the Minnesota Vikings' punter for four seasons, averaging 43.2 yards per punt before going to Indianapolis this offseason. The Colts, however, released him last month.
Locke was signed after Detroit had punter workouts Monday after Redfern tore the ACL, MCL and part of the patellar tendon in his kicking leg against the Cardinals.
The Lions have had to go to Redfern and then Locke because starting punter Sam Martin is on the non-football injury list and is ineligible to come off until Week 7. Lions coach Jim Caldwell has declined to answer how Martin's injury occurred and left the podium Monday when he was asked if he was disappointed in Martin for getting hurt during the offseason.
Detroit also signed offensive tackle Emmett Cleary, who was with Dallas last season. To make room for Cleary, the Lions placed tackle Corey Robinson on injured reserve with a foot injury. Robinson was inactive Sunday and had spent the entire preseason on the physically unable to perform list.