Richardson suffered an oblique injury early in the Colts’ Week 4 win over the Pittsburgh Steelers, exiting briefly before returning, and further aggravating the illness. Veteran Joe Flacco replaced Richardson in the game and helped Indianapolis defeat the previously undefeated Steelers. Flacco started the following week, completing 33 of 44 passes for 359 yards and three touchdowns and nearly leading the Colts to a stunning comeback before falling 37-34 to the Jaguars in the final seconds.

If Richardson is able to play, he will do so without running back Jonathan Taylor (ankle), who sat out Friday.

Surprisingly, Richardson may be available to receiver Michael Pittman. According to NFL Network Insider Ian Rapoport, Pittman suffered a back injury in the Week 5 loss to Jacksonville and was expected to miss several weeks, with injury reserve still a possibility. Steichen provided unexpected hope Friday when he told reporters that Pittman — whom the coach called “one of the toughest guys” — practiced Friday and still has a chance to play Sunday. Pittman was actually a full participant and it is questionable whether he can play.

As for the remaining uncertainty, receiver Josh Downs (toe), cornerback Kenny Moore (hip, shoulder) and tackle Braden Smith (knee, ankle) are also questionable for Sunday. Running back Trey Sermon – a key Taylor replacement – ​​is on track and participating fully in practice.