McKinnon did not appear in last week's game against the Carolina Panthers because of the same injury, which kept him out of practice all this week as well.
McKinnon leads the team in both carries, with 113, and in rushing yards, with 538. The third-round draft pick from Georgia Southern has appeared in 11 games this season, and in addition to his 538 rushing yards, has 135 yards from 27 receptions.
Barr has been dealing with a knee injury sustained in Chicago on Nov. 16; he played last Sunday against the Panthers but left the game when the injury became too painful. Barr has not missed a game this season and has 70 tackles, four sacks, three fumble recoveries and two forced fumbles.