Commanders RB Brian Robinson out Sunday with hamstring injury.

ASHBURN, Va. -- Washington Commanders running back Brian Robinson won't play Sunday vs. the Los Angeles Rams because of a hamstring injury.

Robinson suffered the injury in the 45-10 loss to the Miami Dolphins on Dec. 3 and, following Washington's bye, did not practice this week. Robinson leads Washington with 664 yards rushing and is tied for first with five rushing touchdowns.

In Robinson's past six games, he has averaged 4.5 yards per carry with 10 rushes of 10 or more yards. In the first seven games of the season, he averaged 3.8 yards per run and had only eight carries for 10 or more yards. Robinson also has become more of a receiving threat this season, with 29 receptions for 326 yards and three touchdowns.

Antonio Gibson and rookie Chris Rodriguez will split Robinson's duties. Gibson, who has served as Washington's primary third-down back this season, has caught 37 passes for 322 yards and two scores. Coach Ron Rivera said Jonathan Williams, who is on Washington's practice squad, will be elevated and might play as well.

Gibson has rushed for 193 yards, averaging 4.2 yards per run. Rodriguez has rushed for 154 yards, averaging 5.0 yards per carry.

"I feel good about all three of them," Rivera said. "We want to see more of Chris as well. The big part for him is understanding how to play fast. It's a little different when you get to this level to play with good tempo and good speed and at the same time have a natural feel for the inside and outside zone [runs]."