McKinnon grabbed his right leg on his third carry of drills. There was no contact on the play, but the running back looked very uncomfortable afterward. The team's training staff examined McKinnon before he walked off under his own power.
McKinnon slapped hands with general manager John Lynch upon reaching the sideline, where he spent the remainder of practice. He will undergo an MRI on his right knee at Stanford Hospital to determine the severity of the injury.
The 49ers are already without running back Matt Breida, who sustained a separated shoulder during the 49ers' exhibition opener against the Dallas Cowboys. While Breida is expected to be ready for Week 1 of the regular season, McKinnon's injury leaves the 49ers without their numbers one and two running backs.
The potential absence of both McKinnon and Breida could create an increased workload for running backs Joe Williams and Raheem Mostert. Williams did not practice on Sunday. He was on the East Coast for the funeral of his brother-in-law.
The 49ers have one more practice scheduled for Monday before the team travels to Houston for two joint practices with the Texans leading up to a game between the two squads on Saturday, August 18.
The 49ers signed McKinnon to a four-year deal in March, and the running back has had a solid offseason. During Thursday's game against the Cowboys, however, he rushed for -4 yards on three carries.
Other running backs on the roster include Jeremy McNichols and Jeff Wilson.
Related News
More San Francisco 49ers News
-
Kyle Shanahan shares 49ers updates headed into the bye week
San Francisco 49ers head coach Kyle Shanahan spoke with reporters during a conference call on Monday, one day after the team's 29-20 loss to the Atlanta Falcons. The 49ers are headed into their bye week. Transcript provided by the San Francisco 49ers Communications... -
Former 49ers running back arrested after police chase
According to the New York Post, former San Francisco 49ers running back Joe Williams was arrested in West Hollywood on Wednesday after reportedly leading authorities on a chase. 49ers fans may remember Williams as a member of general manager John Lynch and head coach Kyle... -
49ers' Renardo Green addresses Kyle Shanahan sideline confrontation, game slowing down
San Francisco 49ers cornerback Renardo Green has recorded three interceptions this season, three more than the rest of the defense combined. Last season, however, it appeared head coach Kyle Shanahan might have been losing patience with the young defensive back. The two were... -
49ers insider predicts 'two or three trades' ahead of deadline
The previously unbeaten San Francisco 49ers exposed some weaknesses in Sunday's upset loss to the Atlanta Falcons. While players returning from injury in the coming weeks should help, San Francisco Standard writer Tim Kawakami believes general manager John Lynch could make...