Castonzo was selected with the 22nd overall pick of the 2011 NFL Draft by the Colts, drafted to protect Peyton Manning's blindside. Thanks to Manning's four neck surgeries, a lost 2011 season and the divorce that followed, he never got that chance.
Instead Castonzo's been charged with protecting just as valuable an asset, shoring up the blindside of Andrew Luck after the latest franchise quarterback was taken with the No. 1 overall pick in the 2012 NFL Draft.
Castonzo, one of many notable linemen to graduate from Boston College, will receive a salary (guaranteed for injury only) of $7.438 million in 2015 as a result of the Colts picking up his option.
It was really a no-brainer for Indy: He's a potential franchise left tackle and currently an above-average player at the position.
With its current personnel and a weak division, Indy's got a window to make playoff runs. It would've been foolish to let Castonzo walk onto the market after next season.