Chargers head coach Brandon Staley said Tuesday that Kelley suffered an MCL sprain during Monday's win over the Broncos and will be sidelined for multiple weeks, Jeff Miller of the Los Angeles Times reports.
Kelley was riding the stationary bike after leaving Monday's contest, so the issue didn't initially appear to be too serious. However, Staley's comments suggest otherwise. It's possible Kelley winds up on IR to open up another roster spot, but in his absence, Sony Michel figures to operate as the top backup behind Austin Ekeler.