Scott Horner/IndyStar
The Indianapolis Colts' linebacking core just got thinner.
The team placed veteran Trent Cole on injured reserve Tuesday. The outside linebacker, signed as a high-priced free agent to bolster the pass rush in 2014, has been a disappointment in Indianapolis, amassing just three sacks in 16 games here.
Cole had been battling a back issue in recent weeks and missed the Colts' Week 2 loss in Denver. He played 31 snaps in Sunday's win over the Chargers and finished with one assisted tackle.
More than ever, the onus shifts to Robert Mathis.