The Indianapolis Colts added wide receiver Michael Pittman to their Week 5 injury report Thursday with a hamstring issue. Pittman was a limited participant in practice on Thursday ahead of Sunday’s home game against the Las Vegas Raiders. The Colts enter Week 5 with a plus-40 point differential that ranks fourth in the NFL. Defensive end Tyquan Lewis (oblique) also landed on Thursday’s injury report. Veteran cornerback Xavien Howard abruptly retired for family reasons earlier in the week after starting each of the Colts’ first four games.