Updated

San Diego Chargers outside linebacker Melvin Ingram tore the ACL in his left knee during Tuesday's offseason training activities session, an injury that could sideline the 2012 first- round pick for the entire upcoming season.

Ingram, the 18th overall selection in last year's draft, compiled 41 tackles, one sack and five passes defensed while appearing in all 16 games and starting twice as a rookie. The 24-year-old was expected to hold down a regular role this season following the departure of veteran Shaun Phillips through free agency.

A timetable for Ingram's recovery will be determined once surgery is performed.