SANTA CLARA -- When running back Jerick McKinnon went down with a torn anterior cruciate ligament in his right knee on Saturday, 49ers coach Kyle Shanahan had to rethink his past six months of planning.
That’s because Shanahan insisted that the 49ers’ front office sign McKinnon, a running back he felt was the most perfect of the available offseason options and an improvement over Carlos Hyde.
“You don’t get anything down on paper and give it to your team, but since the day we signed him we’ve been game-planning for Minnesota,” Shanahan said. “So I’m not going to lie. It changes things pretty drastically. That was our first target in free agency, so once you do it, you have a plan on how to use him, especially going into Week 1. So that definitely changes.”
The 49ers open the regular season on Sunday against McKinnon's former team, the Minnesota Vikings.
McKinnon sat out the final three preseason games after sustaining a strained muscle high on his right calf during a practice on Aug. 12. It is unclear whether that injury contributed to the season-ending knee injury he sustained on Saturday during a routine outside run play.
“Yeah, it sucks,” 49ers quarterback Jimmy Garoppolo said. “For a guy who works as hard as he does and puts as much as he puts into this team, it’s tough. But, you know, we’ve got to move on. Injuries happen in this league. That’s kind of part of it.”
McKinnon missed five games as a rookie with the Vikings due to a back injury. In the past three years, he missed just one game due to an ankle sprain. After four seasons with the Vikings used primarily as a backup or a change-of-pace running back, McKinnon received a four-year, $30 million contract from the 49ers as a free agent.
"I’m sorry it happened to Jerick,” Vikings coach Mike Zimmer told Bay Area reporters on a conference call. “He’s a great kid. He was great for us – good hard-worker with a smile on his face every day. I’m sure they’re going to miss him in some ways, but they’ve got some other good backs."
Veteran Alfred Morris was signed before the 49ers second preseason game. He is an inside runner who is not as explosive as either McKinnon or Matt Breida. Morris and Breida will likely share the load. Breida is expected to take more of the outside zone runs and catches out of the backfield.
"These guys are hard workers,” Garoppolo said. “Me and Matt have been going since last year together. It’s good to have him back full-speed now. We’ve still got a good group back there.”
How the 49ers plan to use Morris and Breida is expected to be a week-to-week decision that faces Shanahan and his coaching staff. Breida is returning to practice this week after sitting out the final three games of the preseason with a separated shoulder.
“We’ll see how the week goes,” Shanahan said. “This is Breida’s first full week back from his injury, so we’ve got to see how healthy he is. It probably depends on a lot of personnel groupings, what plays we are running, things like that. So, (I) probably won’t have an idea on that until Saturday night.”
This Sunday, be sure to watch 49ers Pregame Live at 9 a.m. and 49ers Postgame Live immediately after the game on NBC Sports Bay Area and live streaming on the NBC Sports app. Greg Papa, Donte Whitner, Jeff Garcia, Matt Maiocco and Laura Britt will have everything you need to know from the 49ers’ season opener.