ALLEN PARK, Mich. — Jon Kitna's 36-game starting streak with the Detroit Lions is in jeopardy.

Kitna missed a second straight practice Thursday because of an injured back, leaving Dan Orlovsky and Drew Stanton to split snaps.

Lions offensive coordinator Jim Colletto said the team might not know if Kitna can play against the Minnesota Vikings on Sunday until pregame workouts.

Orlovsky replaced Kitna during the third quarter of 34-7 loss to Chicago on Sunday, the first playing time of his four-year career. Orlovsky hurt his ankle and knee, but Colletto said he was healthy enough to practice. Stanton, a second-round pick last year, was on injured reserve as a rookie and hasn't played this season.