Malcolm Brown establishing himself as Todd Gurley's backup

Malcolm Brown had 18 carries for 39 yards last season with the Rams. Kirby Lee/USA TODAY Sports

IRVINE, Calif. -- The Los Angeles Rams signed Lance Dunbar over the offseason to serve as both a backup to Todd Gurley and also a supplemental piece, as a versatile running back who specializes in catching passes out of the backfield. But Dunbar hasn't been able to practice. He's dealing with a lingering knee injury and there's no timetable for his return, which means there's now a major void behind Gurley.

Apparently Malcolm Brown is filling it.

Rams coach Sean McVay said after practice on Monday that he's been "pleasantly surprised" with Brown, who has "done a nice job of establishing himself in that secondary role."

"He's got a quiet confidence about himself, where he just goes about his business, very reliable, knows exactly what to do and how to do it," McVay said. "He's a guy that we can depend on."

Brown was an undrafted free agent out of Texas in 2015 and received only 22 carries, for 56 yards, in his first two seasons in the NFL. Without Dunbar, though, the Rams don't have much of any experience behind Gurley. The only other options are an undrafted free agent from 2016, Aaron Green, and three undrafted free agents from 2017 -- Justin Davis, De'Mard Llorens and Lenard Tillery.

If Dunbar doesn't get healthy, the Rams may have to eventually address the running back position from the outside. The Rams were recently linked to free agent Rashad Jennings, an excellent pass blocker who has rushed for 3,772 yards and caught 191 passes for 1,469 yards during his seven-year career. Others will surely become available later in training camp.

"I think we're looking to find who those guys are to be able to complement that room, and that's something that's ongoing," McVay said. "That's why you're excited about the competition. You've got guys like Aaron Green and Justin Davis; they've shown some flashes. But we'll be able to continue to monitor that and evaluate it moving forward."