ALLEN PARK — Cornerback Jacob Lacey became the Detroit Lions’ fourth defensive back to be placed on injured reserve when the Lions made the move on Tuesday.

 Lacey’s knee cap popped out — a knee subluxation — early in Sunday’s loss at Arizona. It popped back in, but he couldn’t get back up to speed. 

  Coach Jim Schwartz said it won’t require surgery.

  Lacey joins rookie cornerback Bill Bentley and Chris Greenwood, along with safety Amari Spievey.

 To fill his spot on the roster, the Lions signed veteran cornerback Ron Bartell who was cut by the Oakland Raiders on Dec. 10. Bartell, a Detroit native, attended Detroit Renaissance and played at Howard University.

 The Lions (4-10) play the Atlanta Falcons (12-2) on Saturday night at Ford Field. Kickoff is 8:30 p.m. It’s a nationally televised game — Monday night football on Saturday.

 (Follow @PaulaPasche on Twitter.)