A first year starter last year the 6'2" 290lb Ricardo Mathews made 2nd team all Big East with 12.5 tackles for a loss, 3.5 sacks and 2 QB hurries. He's an athletic tackle running a 4.8 40 at his pro day and showed solid strength and explosiveness too with 27 bench reps and a 31.5 inch vertical.
Mathews seems like a player who could grow into an effective 3-tech, bringing some size and disruptiveness to the position.
Kavell Conner seems to fit into the SAM position. He's strong against the run and has some pass rushing skill, but only average in coverage. He has decent size at 6 foot 240lbs. Conner should be a valuable special teamer and has a shot to emerge down the road at SAM. Conner was a 2 year starter with very good production at Clemson.
Ray Fisher is a player in the vein of T.J. Rushing. Officially a returner/CB, it's probably not expected for him to contribute seriously to the defense, but he fills the hole the Colts have returning kickoffs and punts.