Washington Football Team rookie running back Antonio Gibson was diagnosed a turf toe injury, multiple media outlets reported on Wednesday.

Gibson sustained the injury during the first quarter of Washington’s 23-17 victory over previously unbeaten Pittsburgh on Monday. The 22-year-old’s availability is in question as Washington (5-7) plays a road game against the San Francisco 49ers (5-7) on Sunday (4:25 p.m. ET).

Gibson leads the team in carries (141), rushing yards (659) and rushing touchdowns (11), with 75, 402 and eight being recorded during a five-game stretch prior to Monday’s contest. He was selected by Washington in the third round of the 2020 NFL Draft.

J.D. McKissic likely would receive additional playing time should Gibson sit out against the 49ers. A pass-catching running back, McKissic caught all 10 of his targets for 70 yards versus Pittsburgh.