The Colts open training camp Sunday with a great deal of uncertainty and excitement surrounding the team. Rookie quarterback Andrew Luck, of course, provides much of the excitement, but his supporting cast remains in flux.
RB -- Delone Carter vs. Donald Brown
Neither player was particularly effective in 2011 -- well, if we're honest, no Colt was particularly effective in 2011 -- but they'll be looked upon to provide a solid running attack to supplement Luck under center. Brown is expected to start the season behind Luck, but both Carter and rookie Vick Ballard are better suited for coach Chuck Pagano's power running game.
TE -- Coby Fleener vs. Dwayne Allen
Both players will certainly see plenty of action as replacement for the departed Dallas Clark. Fleener will start camp with something of a leg up, as he and Luck have already built a relationship from their days at Stanford. Both guys are solid pass-catchers, and perhaps the better blocker will find himself on the field more -- at least in the beginning.
CB -- Cassius Vaughn vs. Kevin Thomas
Jerraud Powers is firmly entrenched as a starting corner, but there's still a race to fill the opposite side. Some reports state that Thomas, who worked out with Powers in the offseason, is the early favorite to nab the job. Vaughn, who comes to Indy from Denver, has only a single interception in his two-year career. In any event, whoever comes out on top will certainly have to improve their game if they want to have a formidable defensive backfield.
For more up-to-the-minute news and analysis from Colts blogger Evan Hilbert, follow @CBSSportsNFLIND