Colts linebacker Dwight Freeney has spent more time on the sideline than the field this season. (US Presswire)

The Indianapolis Colts' defense was one of the worst units in the league last season, so expectations were tempered heading into 2012. However, several offseason acquisitions and a coaching staff overhaul provided a renewed sense of optimism. And, generally speaking, the defense started the season well before a rash of injuries depleted the unit to a shell of its former self.

Several starters have missed time this season, including cornerback Vontae Davis, linebacker Pat Angerer, linebacker Dwight Freeney, linebacker Robert Mathis and nose tackle Fili Moala. There has been a revolving door on the defensive side of the ball, leading interim coach Bruce Arians to joke: "It’d be nice not to keep learning guys’ names on Sunday.”

This week is no exception. Seven defensive players were limited or out of practice Wednesday, and Arians can only hope that some may be available Sunday.

"We’ll wait to see how [it] goes as the week progresses, but they are making really nice progress and the doctors have not ruled them out yet,” Arians said of the seven, before adding that it was possible that each could see some time against the Browns.

And the Colts will need them. A banged up front seven was shredded last week by bruising Jets back Shonn Greene, and Cleveland will surely try to replicate that performance with either Trent Richardson or Montario Hardesty.

"Once you open up the can of worms, they’re going to jump on it," Arians said of opponents employing a power run game. "Until you put that fire out and make them go somewhere else, they’re going to keep pounding it. Just like when you’re a kid and you found a mud hole, you stomped all the water out of that thing until you went to find another one. It’s the same thing here. They’re capable of it, and we’ve got to put that out.”

Rookie quarterbacks to meet: Rookies Andrew Luck and Brandon Weeden will meet Saturday in a battle of the two most prolific rookie passers in the NFL. Weeden and Luck are first and second respectively in passing yards for rookies, and both have thrown seven touchdowns. Weeden, however, has the edge in interceptions with 10 to Luck's seven.

Notable roster moves: The Colts again played musical chairs with its practice squad and active roster, but did make a couple of notable signings. Defensive end Lawrence Guy was brought in off the Green Bay practice squad. Guy (6-4, 300) was originally drafted by the Packers in 2011 but spent the season on injured reserve. Indy also signed tight end Weslye Saunders, who was waived by the Steelers. Saunders (6-5, 270) is a big target that will likely be used in goal-line situations to complement tight ends Dwayne Allen and Coby Fleener.

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