Luck is expected to see more time than he did last week against St. Louis, when he threw for 188 yards and two touchdowns. Though the Steelers won't be at full strength, they are expected to be less flimsy than the Rams defense.
Here are a few things to watch for:
1. Running back play: All eyes will be on Luck, but there is a running back battle afoot. Starter Donald Brown was impressive in the opener, while Delone Carter and rookie Vick Ballard also showed potential. Not only will the rushing attack be a focus, but they will also be tasked with keeping oncoming Pittsburgh rushers off Luck. Perhaps who's best at the latter will gain a leg up in the battle for playing time.
2. Luck: Of course, Luck will be on display, but again, the circumstances are much different than a week ago. Not only will Luck be facing a stout defense, he'll be experiencing his first road game as a professional. And though it's preseason, you can bet the Steelers defense is chomping at the bit to get a shot at the highly touted rookie. Protection will be vital.
3. Pass catchers: Rookies T.Y. Hilton and LaVon Brazill made a splash in their debut, and Austin Collie was solid, as well. Reggie Wayne -- the veteran of the corps -- was only targeted once, while rookie tight ends Coby Fleener and Dwayne Allen were pretty ordinary. The Colts will have Donnie Avery Sunday for the first time, but it would be nice to see a more sustained effort from Luck's targets.
4. Replacing Angerer: Linebacker Pat Angerer is out for up to six weeks with a broken foot, and Jerrell Freeman will have the first crack at replacing him. Look for Moise Fokou and Greg Lloyd, though, as they will probably get a look as well at Angerer's inside linebacker spot. The newly acquired Mike Balogun will have his first opportunity to make an impression as well.
5. The other side: Jerraud Powers is the starting right corner. This much is known. The other corner, however, is yet to be determined. Justin King will get his shot, as well as Cassius Vaughn. The Steelers will throw the football, so Sunday offers an opportunity for one of the two to create some distance.
For more up-to-the-minute news and analysis from Colts blogger Evan Hilbert, follow @CBSSportsNFLIND.