Marcus Mariota Injury Leaving Sportsbooks Exposed in Colts-Titans Matchup

Tonight's Indianapolis Colts-Tennessee Titans matchup on Sunday Night Football is essentially a Week 17 playoff game with the winner advancing to the postseason.

Titans quarterback Marcus Mariota suffered a stinger last week against the Redskins that forced him to leave the game.

While there was optimism throughout the week that Mariota could tough it out against the Colts, multiple outlets are reporting that he won't be able to play because there is a risk of further, and even permanent damage.

Should Mariota not be able to go, backup Blaine Gabbert is expected to start for Tennessee.

Oddsmakers have reacted to the prospect of Gabbert under center, moving the line from Colts -3 to -4 shortly after news of Mariota's status broke.

While technically only a "one-point line move," this adjustment is significant because of the frequency of how often NFL margins of victory land on both three and four.

At the time of writing, 73% of tickets and 75% of dollars wagered on the spread are on Indy, and most of that action came in before the Mariota news and subsequent line move to -4, meaning the majority of those bettors are locked in at a great number.

With sportsbooks now exposed due to massive Colts liability, it'll be interesting to monitor whether they continue to adjust this line in order to attract Titans money.

Be sure to download The Action Network's mobile app to track real-time odds and betting updates for Colts-Titans, as well as today's entire slate of NFL Week 17 games.