Sources: Steelers RB Jaylen Warren uncertain for Week 1

Jaylen Warren 's status for the Pittsburgh Steelers ' season opener is uncertain because of a hamstring injury that will sideline the star running back for multiple weeks, sources confirmed to ESPN.

Warren suffered the injury in the first half of Saturday's preseason game against the Buffalo Bills and did not return.

Steelers coach Mike Tomlin did not provide an official update on Warren after the game, telling reporters the third-year running back would undergo evaluation this week.

The Steelers visit the Atlanta Falcons in Week 1 on Sept. 8.

Najee Harris would see an increased workload if Warren is unavailable, and veteran Cordarrelle Patterson also could see more opportunities at running back.

The Steelers, who struggled offensively in Saturday's 9-3 loss to the Bills, also are without center Nate Herbig , who is sidelined for a significant amount of time with a torn rotator cuff.

Warren, 25, rushed for 784 yards and four touchdowns last season, averaging 5.3 yards per carry. He also hauled in 61 receptions, the second most on the team, for 370 yards.