The competition for reserve spots on the Steelers' offense should be intriguing, with quarterback, wide receiver and running back positions to watch. At quarterback, the Steelers have three capable backups — Byron Leftwich, Dennis Dixon and Charlie Batch — behind Ben Roethlisberger. Leftwich and Batch are under contract for 2011, but Dixon can be signed away for just a fifth-round pick if the same restricted free-agency rules remain in place in the next CBA. Leftwich was the top backup for much of last season and figures to keep that role in 2011. At wideout, second-year WRs Emmanuel Sanders and Antonio Brown look secure as the top reserves behind starters Mike Wallace and Hines Ward, a source close to the club suggests, leaving veterans Arnaz Battle, Antwaan Randle El and Limas Sweed to contend for spots further down the depth chart. At running back, two potential backups to keep an eye on are Mewelde Moore, who's slated to be an unrestricted free agent; and rookie Baron Batch. Both catch the ball well.