The Indianapolis Colts face a must-win game in Week 17, and there is both good news and bad news. The bad? Offensive lineman Anthony Castonzo is done for the season.

On the one hand, the Colts play the 1-14 Jacksonville Jaguars, which gives Indy a tremendous opportunity to win and–with some luck–reach the NFL playoffs. But even if the Colts nab a playoff spot, they will be without one of their best offensive linemen.

Head coach Frank Reich said Wednesday Anthony Castonzo needs ankle surgery and is done for the year, per James Palmer of NFL Network.

Anthony Castonzo has long been a staple at the left tackle position. He has essentially been entrenched as the starting LT since 2012, and re-signed with the Colts on a two-year deal in March.

The 32-year-old has played in 12 games this season, though he has essentially been battling the ankle issue throughout the year. Castonzo was absent in Week 5 and later missed Week 13 and Week 16 due to the ankle issue. Two of those three games resulted in losses for Indianapolis.

It will be interesting to see how the Colts account for Castonzo's absence in the event they make the playoffs. Will Holden started in Castonzo's place against the Pittsburgh Steelers this past weekend, but left that game due to an ankle injury of his own.

The Colts will need some luck to make the playoffs. They need a win and one of the Tennessee Titans, Baltimore Ravens, Cleveland Browns or Miami Dolphins to lose. A win and a Titnas loss would actually crown the Colts AFC South champions.

In the meantime, Indy also needs to figure out how best to replace Castonzo.