The 49ers signed Tevin Coleman to join McKinnon (knee) and Matt Breida (ankle) at running back, Jennifer Lee Chan of NBC Sports Bay Area reports.
Speaking a couple weeks ago, coach Kyle Shanahan said he expects McKinnon to handle the lead backfield job in 2019, with the prized signing from last offseason making good progress in his recovery from the ACL tear he suffered Sept. 1. The addition of Coleman creates some doubt about the 49ers' confidence in Breida and McKinnon, but there hasn't been any suggestion the latter is in danger of being released before Apr. 1 when his 2019 base salary ($3.7 million) will become guaranteed. Assuming he sticks around and makes a full recovery, McKinnon will be part of a three-way battle for playing time this summer.