Colts left tackle Anthony Castonzo returns to practice, sign Will Holden from Ravens

INDIANAPOLIS — A perilously thin Colts tackle situation got a welcome sight on Thursday.

Anthony Castonzo, back on the practice field.

Castonzo, the Colts' long-time starter at the left tackle position, suffered a sprained MCL in the first half against Tennessee two weeks ago and was forced to miss Sunday's win over the Houston Texans because of the injury, which typically carries a recovery timetable of three to six weeks.

But the Colts and Castonzo appeared to be optimistic from the start that the veteran tackle might be able to return ahead of schedule. Castonzo was not placed on injured reserve, which would have required him to sit out three weeks, and he practiced on a limited basis on…