McCaffrey (oblique/ribs) is scheduled to undergo an MRI on Monday, Matt Barrows of The Athletic reports.
Head coach Kyle Shanahan noted Monday that a determination hasn't been made whether the injury that forced McCaffrey out of Sunday's loss to the Browns is an oblique issue, a rib issue or a combination of the two. Once the results of the running back's MRI are available, the 49ers should have a better idea of McCaffrey's availability for next Monday's game against the Vikings. If McCaffrey ends up sitting out Week 7, Jordan Mason and Elijah Mitchell would be in line to lead the San Francisco backfield.