By Nick WagonerESPN Staff Writer
After limping to the side to receive attention from the medical staff and sitting out the rest of practice, McKinnon was slated for an MRI to check for potential structural damage on Sunday afternoon, according to the team.
McKinnon opened Sunday's practice with a couple of long runs off the right side but a little later came up gimpy after another play. He hobbled to the side, where the Niners' athletic trainers spent about 10 minutes examining him.
McKinnon pointed to the back of his right knee as he spoke to the medical staff before he eventually stood back up, slapped hands with general manager John Lynch and walked back to join his teammates. He watched the rest of practice and took photos and signed autographs for fans in attendance when it was over.
The results of his MRI were not yet available early Sunday afternoon.
McKinnon, who signed a four-year, $30 million deal with the 49ers in the offseason, suffered his injury only a few days after backup Matt Breida left Thursday's preseason opener with a separated shoulder. Breida is expected to miss the rest of the preseason but be ready for the season opener on Sept. 9 at...