Can Marcus Mariota resurrect career as Bears' Mitchell Trubisky's backup?

Reinhold Matay/USA TODAY Sports

LAKE FOREST, Ill. -- Chicago Bears starting quarterback Mitchell Trubisky finished the regular season 28th in total QBR (39.4), tied for 27th in touchdown passes (17), 21st in passing yards (3,138), 32nd in yards gained per pass attempt (6.1) and 28th in traditional quarterback rating (83.0).

General manager Ryan Pace already anointed Trubisky -- drafted second overall in 2017 -- as Chicago’s starter heading into the 2020 season, but the Bears desperately need to upgrade the backup spot.

The list of potential free-agent quarterbacks is star-studded. Future Hall of Famers Tom Brady, Drew Brees, Philip Rivers and Eli Manning could all (theoretically) test the market. Dak Prescott, Jameis Winston and Teddy Bridgewater could also land lucrative extensions or deals with quarterback-needy teams.

Ryan Tannehill -- another quarterback on an expiring contract -- has the Tennessee Titans one victory away from the Super Bowl. By all appearances, Tannehill is in a pretty good situation with the Titans, who have the league's leading rusher, Derrick Henry, on the roster.

The Bears, on the other hand, are a little less attractive. Chicago ranks near the bottom in projected 2020 salary cap space and is still without a first-round pick because of the Khalil Mack trade (Pace currently possesses a pair of second-rounders, and drafting another developmental quarterback has to be an option).

Trubisky counts $9.23 million against the cap next year by virtue of his fully guaranteed base salary and prorated signing bonus, but the final cost of Trubisky’s four-year rookie contract will be $29.032 million. Unless the Bears reexamine their stance on Trubisky starting, they will not sign a quarterback with any star power.

The offense -- led by Trubisky -- was 29th in points, 29th in average yards per game, 25th in passing yards and 27th in rushing yards. And the Bears have reached the playoffs only six times (three wins) since 2000.

Given all these constraints, the Bears need to find their version of Tannehill -- a former starter who for whatever reason fell out of favor with his current team, wants a fresh start and (this is important) has no other choice but to play the role of backup until/if the time comes to replace Trubisky.

The Titans got incredibly lucky with Tannehill. But there are a couple of veteran quarterbacks who fit the criteria.

Marcus Mariota: Another former second overall pick, Mariota’s time in Nashville is almost up. The Titans turned to Tannehill in Week 6 and haven’t looked back. The Bears could do a heck of a lot worse than Mariota, who has plenty of NFL starting experience and won the Heisman Trophy in college. Mariota probably -- at the right price -- sees an opportunity to eventually win the job. Unless Mariota can sign somewhere as the starter, Chicago checks a lot of boxes in this particular circumstance.

Case Keenum: The 31-year-old quarterback parlayed his magical run in Minnesota into a two-year deal with Denver that lasted just one season before he was traded to Washington, where he was benched for rookie, first-round pick Dwayne Haskins Jr. Still, Keenum walked away with great money (more than $20 million) for his troubles. Keenum has been part of five organizations and appeared in 67 regular-season games and two postseason contests.

Matt Moore: The Bears already had a pair of former Kansas City backups (Chase Daniel and Tyler Bray) in their quarterback room the past two seasons. But Moore is slightly different. The 35-year-old is a former starter who filled in admirably when Patrick Mahomes (knee) had to miss a couple of weeks of the regular season. The biggest plus is that Moore knows the offense. And he’s a good athlete.