Head coach Jim Harbaugh told reporters Wednesday that Colson's placement on the active/non-football illness list is due to an appendectomy, Eric Smith of the Chargers' official site reports.
The rookie linebacker out of Michigan was placed on Los Angeles' active/non-football illness list one week ago, and the timetable for his return is currently unknown. Once Colson recovers from his appendectomy, he's expected to serve as one of the Chargers' top inside linebackers.