"It wasn't even a full practice," Rapoport reported on NFL Network. "It didn't really seem like there was much there but he suffered a non-contact injury just making a cut. Went down. It was very clear to the 49ers this was serious."
"He made a cut on air," head coach Kyle Shanahan told reporters. "It was the last play of practice. Made a cut on air. No one was around him. Just went down. It looked awkward."
The 49ers later confirmed that McKinnon tore his ACL and would be undergoing season-ending surgery.
"Right off the bat, I am told [the 49ers] are crushed by this injury," Rapoport continued.
McKinnon had not played since the 49ers exhibition opener on August 9. Three days later, he sustained a calf strain during practice and was not slated to play again until the regular season opener against the Minnesota Vikings.
Shanahan said that Saturday's practice was McKinnon's first time participating in 11-on-11 drills since the calf injury.
The 49ers signed McKinnon in March to a four-year deal worth up to $30 million. He was intended to become the team's featured back within Shanahan's offense.
The Vikings made McKinnon a third-round draft pick in 2014. He registered 1,918 yards on 474 carries with seven touchdowns in four NFL seasons. McKinnon also added 94 receptions for 676 yards with four touchdown catches since 2016.
49ers defensive coordinator Robert Saleh is well aware of the matchup problems McKinnon created for opposing defenses. Saleh saw the running back as a dangerous receiving option for the offense, almost like another wide receiver.
"A wide receiver who can carry the ball and carry it with power the way he does," Saleh said in August. "He's another dynamic football player that's got to be accounted for."
The other running backs on the roster after Saturday's 53-man cut-down are Matt Breida, Alfred Morris, and Raheem Mostert.
Related News
More San Francisco 49ers News
-
49ers' Trent Williams, Fred Warner amazed by Nick Bosa's recovery after ACL injury
For the second time in his NFL career, San Francisco 49ers defensive end Nick Bosa had his season cut short by an ACL injury. The latest setback occurred in Week 3 of the 2025 season. The good news is that the timing of the injury allowed Bosa ample time to recover and prepare... -
First look: 49ers DE Nick Bosa practices with teammates after ACL injury
San Francisco 49ers defensive end Nick Bosa was not among the four players placed on the active/physically unable to perform (PUP) list to open training camp, signaling that he has been fully cleared to participate. Bosa is returning from the torn ACL he suffered last... -
49ers coach Kyle Shanahan admits car accident was his fault, corrects initial report
San Francisco 49ers head coach Kyle Shanahan met with reporters on Tuesday in his office, marking his first media availability since the July 14 car accident that left him with several injuries. Initial reports indicated that the other driver—a 21-year-old woman behind the... -
Bleacher Report names Mac Jones 49ers' most important contract decision heading into 2026 season
The San Francisco 49ers have one of the NFL's more enviable situations at quarterback heading into the 2026 season. Brock Purdy is firmly established as the team's starter, but the 49ers also have a proven backup in Mac Jones who showed last season that he can step in and keep... -
Report: 49ers work out veteran edge rusher Ogbo Okoronkwo
The San Francisco 49ers are taking a look at another veteran option for their defensive line. According to NFL Network's Ian Rapoport, veteran free-agent edge rusher Ogbo Okoronkwo worked out for the 49ers on Sunday. Veteran free agent edge Ogbo Okoronkwo, who played last year...