Jerick McKinnon’s first 49ers season is likely over before it started.
A week before squaring off against his former team in the season opener, San Francisco’s new $30 million running back suffered a torn ACL in his right knee, the 49ers confirmed, meaning he is all but assured to miss the entire 2018 season. McKinnon underwent an MRI on Saturday.
The injury happened during a short informal practice on Saturday as San Francisco cut the roster down to 53 players. McKinnon was working his way back from a calf strain suffered during practice Aug. 12 and was expected to make his 49ers debut on the road against the Minnesota Vikings.
“He made a cut on air,” Kyle Shanahan said Saturday during a conference call. ”No one was around him, he went down. (It) looked awkward.”
The 49ers dealt with a slew of minor injuries throughout training camp and the preseason. Until Saturday, the team was optimistic it would be in good health ahead of the trip to Minnesota.
McKinnon, his backup Matt Breida (shoulder) and tight end George Kittle (shoulder) were all expected to be available after suffering injuries in August. Additionally, defensive lineman Arik Armstead returned in the third preseason game after suffering a hamstring injury, as did Solomon Thomas following a concussion in the exhibition opener.
McKinnon played just one preseason series with his new team. He signed a four-year, $30 million contract, becoming one of the league’s richest running backs. The deal included $11.7 million guaranteed at signing.
Breida and recent addition Alfred Morris are likely to shoulder the load in McKinnon’s absence. Morris was brought in after the 49ers’ top two backs hit the shelf with their injuries last month. He made a strong first impression in the exhibition against the Colts by rushing for 84 yards on 17 carries, helping put together San Francisco’s best rushing performance of the preseason. He spent the past two seasons as Ezekiel Elliott’s backup in Dallas after beginning in his career playing for Shanahan in Washington, where he averaged 1,321 yards in his first three seasons while notching 28 touchdowns.
But neither is as dynamic as McKinnon, who was a prominent weapon throughout training camp both in the running game and as a pass catcher. McKinnon ran a blistering 4.41 at the NFL combine in 2014 while posting an impressive 32 bench reps to rank in the 98th percentile at his position.
Shanahan considered McKinnon one of the league’s most versatile threats with the ability to help the team in the passing game in key situations.
“I think he’s an extremely good runner. I’ve loved him since college,” Shanahan said in March after watching McKinnon play quarterback for Georgia Southern. “What is a huge bonus on him is when you talk about the pass game. When it comes to separating and beating linebackers and safeties in man-to-man coverage, I definitely think he’s an issue for teams. I think this league, when it comes to third downs and things like that, you move the chains based off of matchups, which allows you to get points in the long run.”
Final cuts came before the 49ers knew of the severity of McKinnon’s injury, which forced them to give him a spot on the 53-man roster. The team could have the option to bring back Joe Williams, Jeremy McNichols or undrafted rookie Jeff Wilson Jr., who were also released during final cuts. Williams, a fourth-round pick in 2017, became the first draftee of the Shanahan and John Lynch regime to get released.