Once Anthony Castonzo went down last week with what was diagnosed as an MCL sprain, it was clear that there were going to be changes along the offensive line for the Colts. Castonzo is described as week-to-week and isn't playing today, so that means the Colts needed a different starter at left tackle for the first time since 2011.
As expected, starting right tackle Joe Reitz started at left tackle today in place of Castonzo, and then to replace Reitz at right tackle, rookie Denzelle Good made his NFL debut as the starter. The interior of the offensive line remained the same, as Jack Mewhort started at left guard, Jonotthan Harrisonat center, and Hugh Thornton at right guard.
Good was the Colts' seventh round pick in this year's NFL Draft out of Mars Hill, and he is a guy the Colts were excited about. He played well in training camp and preseason while working with the second team offensive line, and perhaps the most impressive and noteworthy aspect is that the Colts kept Good on the active roster all season. He was inactive for the first ten games, but the fact that the Colts kept a seventh round rookie who was a constant inactive on the roster all season without moving him down once should tell you everything you need to know about how much the Colts like him. Today, they started him at right tackle, as we thought they might after he worked there during practice this week.
The Colts liked Reitz at left tackle during camp and worked him there with the second team unit, showing that if Castonzo were to miss time it would almost certainly be Reitz stepping in. That's exactly what happened, and the Colts then decided to insert the rookie at right tackle to ensure as little change as possible.