There is a "real chance" Christian McCaffrey is out again for the 49ers' Week 2 game against the Vikings according to Adam Schefter of ESPN.

McCaffrey is dealing with a calf and an Achilles issue that kept him out of most training camp and preseason activities.  CMC was a last-second scratch Monday night against the Jets, leaving Jordan Mason to run roughshod over New York’s defense to the tune of 147 yards and a touchdown.

It appears McCaffrey’s injury is far more serious than first thought. Mason will be a top-12 running back option until CMC can return.