McCaffrey could reportedly return as soon as Oct. 20.
The Vikings promoted safety Bobby McCain and running back Myles Gaskin from the practice squad to the active roster for Sunday's game against the Jets.
A day before the Week 5 home game against the Cardinals, the 49ers have placed a player on injured reserve, and activated one from IR.
The Chiefs need their other receivers to step up, in the absence of Rashee Rice.