Jerick McKinnon has reportedly torn his ACL and is expected to miss the entire 2018 season. The league’s fifth-highest paid running back was locked in as the 49ers starter, and McKinnon was expected to be used as a three-down back in Kyle Shanahan’s historically fantasy-friendly offense.

Who Starts at Running Back for the 49ers Now?

There are only three running backs remaining on the team’s roster. Beat writer Matt Maiocco indicates that Alfred Morris is the favorite to start with Matt Breida working in a backup role and Raheem Mostert sticking to special teams. This makes sense given their respective profiles and skill sets.

  • Morris: The 29-year-old was signed off the streets not even three weeks ago, but he showed off his Shanahan-friendly one-cut rushing style to the tune of 84 yards on 17 carries (4.9 yards per carry) in the team’s Week 3 preseason dress rehearsal. Morris was one of just seven backs to average at least 4.6 yards per rush last season (min. 100 carries).
  • Breida: The second-year back suffered a shoulder injury in the team’s preseason opener, but he’s expected to be good to go for Week 1. Breida is a dynamic athlete (88th-percentile SPARQ score) and ranked 17th among all running backs with 5.1 yards per touch last season. The 5-foot-10 and 190-pound back caught 21 passes as a rookie.
  • Mostert: The third-year veteran has nearly five times as many kick returns (26) as rush attempts (7) in his career. The 5-foot-10 and 195-pound special-teamer saw just 136 rush attempts in four seasons at Purdue.

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Of course, Shanahan oversaw Morris’ most productive campaigns as Washington’s offensive coordinator in the running back’s first two NFL seasons.

A committee backfield with Morris serving as the early-down and short-yardage back and Breida handling pass downs seems like the most probable outcome. Morris has never caught 20+ passes in a season, and Breida is capable of handling a fantasy-friendly role as the de facto pass-down back in a high-scoring offense. But it’s likely Morris will secure Shanahan’s goal-line role.

It’s also certainly possible that the team will look to add an additional running back in free agency or via trade.

Does This Affect Jimmy GQ?

Losing an athletic receiving-friendly back like McKinnon certainly doesn’t help Jimmy Garoppolo. Still, Garoppolo fed Carlos Hyde and Breida an average of only 5.5 combined targets per game last season, while they saw an average of 9.1 in Weeks 1-12.

Garoppolo is special: Only Aaron Rodgers has averaged more adjusted yards per pass attempt among all quarterbacks in NFL history (min. 250 pass attempts). McKinnon would’ve helped pick up some easy yards after the catch on screens and option routes, but the fifth-year back’s absence isn’t going to break Garoppolo’s career.

The 49ers averaged 28.8 points per game during the final five weeks of last season. They’ve since bolstered the offensive line, regained wide receiver Pierre Garcon and had an entire offseason to soak in Garoppolo. The loss of McKinnon is far from ideal, but if there’s anyone who can manage with a banged-up backfield, it’s a Shanahan.


Pictured above: Alfred Morris
Photo credit: Brian Spurlock-USA TODAY Sports