The Colts placed Dulin (hamstring) on injured reserve Tuesday.
It's unclear when Dulin suffered the injury, but he'll now be required to miss at least the Colts' next four contests. Through 10 games this season, Dulin has logged a 5-106-0 receiving line on 132 offensive snaps while also seeing 161 snaps on special teams. Anthony Gould and Laquon Treadwell are next up on the depth chart behind Michael Pittman, Alec Pierce and slot man Josh Downs.