AP The 49ers placed running back Jerick McKinnon on injured reserve Monday after he tore his ACL in practice on Saturday. It goes without saying that this wasn’t what the team hoped to see when they signed McKinnon as a free agent this offseason and McKinnon said he was “devastated” when he realized that he would not be OK for a Week One matchup with the Vikings. McKinnon spent the last four years with the team and feels the game “probably meant a lot to me” than other members of the team. McKinnon’s going to be out for a lot more than a week, of course, and he also addressed the rehab process that will start after he has surgery in the near future. “My main thing is just I’m excited for the process,” McKinnon said, via the Sacramento Bee. “It’s going to be a challenge, everything is a challenge. Everybody that knows me knows I love challenges, so I just see it as probably one of the toughest challenges I’m going to have to face, but I’m excited for it.” The 49ers’ plans have been scrambled, but they got a head start on a new approach by signing Alfred Morris after McKinnon strained his calf in August. He’s also played for head coach Kyle Shanahan in the past and the 49ers will be hoping that Plan B turns out to be a successful one.