Mike Tomlin looks forward to “significant step” from Markus Wheaton

The Steelers have lost Emmanuel Sanders and Jerricho Cotchery in free agency, leaving the team with 113 catches to replace from last season’s offense. The draft will likely bring some potential contributors in the passing game and Pittsburgh has signed Lance Moore and Darrius Heyward-Bey, but the Steelers will also be looking to one of…