The Facts: According to multiple reports, McKinnon suffered an injury during a team workout on Saturday.
Diehards Line:HC Kyle Shanahan confirmed that McKinnon hurt his knee in practice today and "we're nervous about it, that's for sure." The exact nature of the injury isn’t known at this time, but Ian Rapoport of NFL Media called it “concerning. ...” The 49ers ruled McKinnon out for the preseason after hurting his knee in a mid-August practice. The idea was to have him ready for Week 1, but that’s up in the air now. Alfred Morris was signed after Matt Breida was also hurt this summer and it appears he may be playing a bigger role than expected.