Los Angeles Rams running back Todd Gurley is listed as doubtful for his team's game against the San Francisco 49ers on Sunday due to a thigh injury, according to Adam Schefter of ESPN.

This is just the latest blow in what has been a disappointing season thus far for Gurley.

On the year overall, Gurley has carried the ball 64 times for 270 yards and five touchdowns, but since rushing for 97 yards on 14 attempts in Week 1, Gurley has failed to average four yards per carry in any of his last four games.

Gurley's struggles have fueled speculation that the three-time Pro Bowler is still being plagued by a knee issue that kept him out for the final two games of last season and severely limited him in the NFC Championship Game and the Super Bowl.

The 25-year-old did not at all in the preseason.

Gurley, who played his collegiate football at the University of Georgia, was originally selected by the Rams with the 10th overall pick of the 2015 NFL Draft.

He had a tremendous rookie campaign, rushing for 1,106 yards and 10 scores while averaging 4.8 yards per carry en route to a Pro Bowl appearance. He followed that up with a lackluster 2016 season before returning with a vengeance in 2017, racking up 1,305 yards and 13 touchdowns on the ground while registering 4.7 yards per attempt. In addition, he caught 64 passes for 788 yards and six scores, making the Pro Bowl and earning a First-Team All-Pro selection as a result.

Then, last year, Gurley totaled 1,251 yards and 17 touchdowns as a rusher, logging 4.9 yards per carry. He also hauled in 59 receptions for 580 yards and four touchdowns and once again earned both Pro Bowl and First-Team All-Pro honors.