Marcus Mariota's promising rookie season ends due to knee injury

Once Marcus Mariota hurt his knee on Sunday at the New England Patriots, it was clear there was a good chance his season would be finished.

Reports on Monday confirmed that Mariota won't play in the Tennessee Titans' last two games. Chris Mortensen of ESPN said he has a sprained MCL, the same injury he had earlier this year that cost him some time. This time the injury is to his right knee; earlier in the season it was his left knee.

The Titans are 3-11 so there's no reason to rush Mariota back. It's also a bad idea for a team to ruin a promising rookie quarterback's future by playing him when he's hobbled and can't protect himself. Ask Robert Griffin III about that.

Mariota doesn't have to prove anything else this season. His first year was a huge success. Assuming his season is indeed over, it ends with 2,818 yards, 19 passing touchdowns and 10 interceptions in 12 games. He also rushed for 252 yards and two scores. He was accurate and picked up the NFL game much quicker than most people expected, after winning a Heisman Trophy in a spread offense at Oregon. He looked like he'd been in a pro style offense for years. He played well from the pocket but still showed off his athleticism when the situation dictated it. He also played at a very high level despite being on a team that doesn't have a lot of talent around him. It was an A-plus of a rookie year.

The injury might cost Mariota a shot at the NFL offensive rookie of the year award. There's a lot of competition, with Tampa Bay Buccaneers quarterback Jameis Winston, St. Louis Rams running back Todd Gurley and Oakland Raiders receiver Amari Cooper also vying for the award. Having injuries shorten his season to just 12 games won't help his case, especially in such a stacked race.

The award is not the most important thing to come out of this season for Mariota, however. He proved that he can be a very good quarterback on the NFL level, and he should only continue to improve if his health cooperates. The future is bright in Tennessee now. They have their franchise quarterback.