McKinnon doesn't believe he or the 49ers took risks in getting him back on the practice field coming off the previous injury -- and he doesn't believe the injuries are related.
"I don't feel like I rushed back," McKinnon told reporters Monday. "That was the plan ... that's what we went with. I felt good at practice. It just so happened, I made a cut and I tore my ACL. That's all it was."
A simple move during an 11-on-11 drill shattered what was one of the more eagerly anticipated storylines of the 2018 season. After signing a four-year, $30 million contract with the team in March, McKinnon was expected to be the go-to guy in the 49ers' running game. Instead, 49ers fans will have to wait another year to see if he's capable of being a strong complement to the Jimmy Garoppolo-led offense.
McKinnon immediately knew his knee was in serious trouble when he went down. Realizing he'd miss the season opener against the Minnesota Vikings -- his former team -- was difficult to accept.
"I was more devastated when it happened, just the feeling knowing that it wouldn't be all right for Week 1," McKinnon said. "This game probably meant a lot to me [than] maybe anybody else, just going against my former team and stuff like that. So, when it happened and I felt it, I would probably say that initial thought of like 'Dang, I'm not going to have a week to get my knee right' was probably the worst feeling."
McKinnon, who was placed on injured reserve Monday, will undergo surgery once the swelling in his knee goes down. Until his return, he plans to be the 49ers' "biggest cheerleader."
"You can't sit here and be down about it the whole time or feel sorry for myself because that's not going to do nothing but just set me back even more," McKinnon said. "I'm here to root these guys on, make sure they stay straight and we all hit our team's goals that we've been talking about since I got here."