Indianapolis Colts left tackle Anthony Castonzo has suffered a mild MCL sprain, according to ESPN's Mike Wells. He is out for the rest of preseason, though the team hopes he will be ready in time for the regular season opener against the Oakland Raiders.
Castonzo left Saturday's win over the Browns with a sprained knee and was replaced by Joe Reitz. An MRI on Sunday confirmed the MCL sprain. Coach Chuck Pagano says he is considered day-to-day.
A first-round pick in 2011, Castonzo played 28 games in his first two seasons, grading out as Pro Football Focus' 32nd best tackle in 2012. Reitz will most likely get the start in Week 1 if Castonzo isn't ready to go. The Colts' offensive line struggled to protect Andrew Luck last season, allowing him to be the most hit quarterback in the league.