49ers RB McKinnon to have MRI after knee injury in practice

Running back Jerick McKinnon is getting an MRI on his right knee this afternoon after leaving practice this morning, the 49ers said.

McKinnon was observed grabbing behind his knee during practice and he watched the rest of the session after he was initially examined by the medical staff.

McKinnon’s premature exit came two days after his backup, Matt Breida, sustained a separated shoulder in the first quarter of a preseason-opening win against the Cowboys. Breida’s injury did not include structural damage and the team is optimistic he will be ready for the season opener against the Vikings on Sept. 9.