Detroit Lions tight end Brandon Pettigrew will not return this season after tearing his ACL in Sunday's loss to the Rams in St. Louis. Coach Jim Caldwell confirmed the severity of Pettigrew's left knee injury Monday. Pettigrew will finish the season with a career-low seven catches. Caldwell called Pettigrew a great leader.  The 30-year-old tight end has played his entire seven-year career with the Lions after being drafted in the first round out of Oklahoma State in 2009.  Eric Ebron, a more recent first-round pick, has become Detroit's top pass-catching tight end. He has 34 receptions for 384 yards and four touchdowns this season.  The Lions (4-9) have been mathematically eliminated from postseason contention.  The Lions head to New Orleans for the Monday Night game next week.