Colts suffer loss they can't afford on O-line

INDIANAPOLIS -- The offensive line is the unit that couldn't afford to miss any practice or game time together for the Indianapolis Colts.

Not after allowing Mr. Franchise -- Andrew Luck -- to be sacked 41 times last season and signing two new starters during the offseason.

First, guard Mike McGlynn suffered a knee injury in practice last week. And now coach Chuck Pagano announced during a conference call with reporters Sunday that starting left tackle Anthony Castonzo is out with a mild MCL sprain.

That means 40 percent of an offensive line that already has question marks is injured. It also means that group played only two preseason games together.

Castonzo suffered the injury on the Colts’ first offensive series of the game against Cleveland on Saturday.

The offensive line hasn't been perfect -- evident by the number of times Luck took a hit or was forced to scramble against the Browns -- but they were showing signs of getting better. Joe Reitz will start at tackle against Cincinnati in the preseason finale on Thursday.

“I thought they’ve done a nice job,” Pagano said. “Those guys are starting to jell and starting to click and they’re coming together every day and they’re getting better every day and they’re working at it. ... You’ve got a little bit of leakage here and there, some pressure.”

The Colts are hopeful Castonzo will be ready for the Sept. 8 regular-season opener against Oakland. Pagano also said McGlynn is “one tough cookie” and that he believes he’ll be ready for the opener, too. If not, the Colts won’t hesitate to use rookie Hugh Thornton, who made his preseason debut Saturday, at guard against the Raiders.