The Washington Redskins will already be without defensive star cornerback Josh Norman, who is dealing with a rib injury suffered during a Week 4 loss to the Kansas City Chiefs. It is looking more and more likely the team will be without one of its key offensive starters when it hosts the San Francisco 49ers on Sunday.

Running back Rob Kelley is a "long shot" to play against the 49ers, according to Washington head coach Jay Gruden. Kelley, who suffered an ankle injury against the Chiefs, has already missed two days of practice this week and is expected to miss Friday as well.

Kelley has started three of Washington's four games this season and rushed for 131 yards on 29 attempts. He was signed as an undrafted free agent out of Tulane in 2016 and carried the football 168 times for 704 yards as a rookie last season.

The injury means the 49ers will likely face rookie running back Samaje Perine with veteran Chris Thompson and Mack Brown splitting relief duties. Perine has rushed for 143 yards on 46 carries this season, including a Week 3 victory over the Oakland Raiders when he gained 49 yards on 19 carries.

Another key offensive player for Washington who has not practiced this week is left tackle Trent Williams. Gruden said the team hopes to have a better feel regarding his status at the end of the week.

The 49ers defense ranks 19th against the run this season, allowing 116.6 yards per game. Finalized injury reports for both San Francisco and Washington will be made available Friday afternoon.