There are few certainties when it comes to the Indianapolis Colts. Andrew Luck will be at quarterback and Reggie Wayne will be split wide, sure, but everything else is in question. On Sunday the process of answering those questions will begin when the Colts take on the St. Louis Rams.

Aside from the development of Luck, Indianapolis will be looking for a reliable backfield, as well as trying to get accustomed to the new defensive scheme. Defensive mainstays Dwight Freeney and Robert Mathis will be getting used to new positions, and a bevy of untested defensive backs will be trying to work their way into the starting lineup.

Further questions worth exploring:

Who will win out at running back?

For now, head coach Chuck Pagano will be looking to fourth-year pro Donald Brown. However, offensive coordinator Bruce Arians wants a punishing running game, which, perhaps, will not be as suitable to Brown as it is to backups Delone Carter, rookie Vick Ballard, and Mewelde Moore, who played under Arians in Pittsburgh. It wouldn't be a surprise to see any one of those players supplant Brown by the season's start.


The current choice for the outside receiver opposite Wayne is Austin Collie, but he's played in the slot throughout his career. It's not that Collie isn't suited to run deeper routes and play wide, but there may be some guys on this roster who could do it better, giving Collie the opportunity to move back to the slot. Donnie Avery, who will sit out Sunday's game with a thigh bruise, could make a run. And don't count out rookies LaVon Brazill and T.Y. Hilton, who have both been impressive in camp.

It will be interesting to see who Luck feels comfortable throwing the ball to. He and Collie have been said to have developed a good relationship, and if rookie Griff Whalen sees the field during the first three or for series' (he's been injured for much of the preseason), Luck may look for his old Stanford teammate.

How will the front seven adapt?

Indianapolis is morphing from a 4-3 to a 3-4 defensive scheme, with Dwight Freeney moving to outside linebacker along with Robert Mathis. Freeney has been said to have made the move fluidly, but Sunday will be his first real live action. Defensive end Cory Redding, who's expected to be a major contributor, will probably sit Sunday's game out with an elbow injury.

Will the DBs be better? The Colts were very shaky in the secondary last season, allowing 71.2 percent of passes to be completed, good for worst in the NFL. They brought in some help in ex-Rams corner Justin King to play opposite Jerraud Powers, but he's been beaten out by Cassius Vaughn in the early going. Safeties Tom Zbikowski and Antoine Bethea will anchor the middle.

For more up-to-the-minute news and analysis from Colts blogger Evan Hilbert, follow @CBSSportsNFLIND