INDIANAPOLIS | Andrew Luck's protectors are now taking their own hits.
Colts coach Chuck Pagano said Sunday that left tackle Anthony Castonzo will not play in the preseason finale after an MRI confirmed Castonzo has a mild sprain of the medial collateral ligament in his right knee. Castonzo was injured on the opening series' of Saturday night's 27-6 victory over Cleveland and did not return. Right guard Mike McGlynn did not play Saturday after bruising his knee during practice last week.
Castonzo is listed as day-to-day, and Pagano said Sunday he hopes both would be ready for the Sept. 8 opener against Oakland.
"The MRI was pretty much negative. It wasn't as bad as anybody anticipated," Pagano said, discussing Castonzo's prognosis during a conference call. "You never want to lose anybody, and particularly the guy who's protecting the blind side of your quarterback."
Joe Reitz will replace Castonzo in the lineup at Cincinnati. Reitz started nine games in 2011 and eight last season, all with the Colts, after being cut by the Ravens in 2010.
Protecting Luck was Indy's top offseason priority after yielding 41 sacks and dozens more hits last season. General manager Ryan Grigson signed right tackle Gosder Cherilus and left guard Donald Thomas in the first hours of free agency — an effort to shore up Luck's protection. Grigson also drafted two offensive linemen, Hugh Thornton and Khaled Holmes, in the third and fourth rounds, respectively.
While Cherilus and Thomas have been solid, the Colts aren't quite sure what they can expect from their injured rookies.
Holmes sprained his right ankle on the fourth day of training camp and hasn't practiced or played since then.
Thornton sprained his right ankle a few days before training camp opened, returned to practice last week and made his preseason debut Saturday.
"He knocked off a little bit of rust, but he looked pretty good in there in both the run and the pass game," Pagano said.
The offensive line isn't the only spot where the Colts are hurting.
Indy's top two tight ends Dwayne Allen (right foot) and Coby Fleener (right knee) sat out against Cleveland, and backup receiver Nathan Palmer left late in the game with a knee injury. Pagano said an MRI confirmed Palmer also has a sprained MCL and is likely to miss four to six weeks — a diagnosis that could jeopardize his ability to make the 53-man active roster.
The Colts have already begun the cut-down process.
On Sunday, they waived 11 players and put backup linebacker Lawrence Sidbury on injured reserve, trimming the 90-man roster to 78. They must be down to 75 by Tuesday.
Sidbury signed on the first day of free agency, a move aimed at helping special teams and bolstering the defense. But he hurt his shoulder in last week's win over the Giants and got a second opinion this past week. Pagano said Sunday he will get another opinion and likely will have surgery.
The Colts also waived cornerbacks Johnny Adams and Allen Chapman, offensive linemen Danous Estenor and Rick Schmeig, defensive tackle Kellen Heard, punter-kicker Brandon McManus, running back Davin Meggett, linebacker C.O. Prime and safety Ashante Williams. Receiver Maurice Williams was waived with an injury settlement. Cornerback Teddy Williams was waived-injured and will revert to Indy's injured reserve if he clears waivers.