OWINGS MILLS, Md. -- Baltimore Ravens running back J.K. Dobbins' long road back from a significant knee injury hit another bump.

Dobbins, the Ravens' No. 1 back, is expected to undergo arthroscopic surgery on his left knee next week that will sideline him four to six weeks, sources told ESPN's Adam Schefter on Friday. The running back did not practice all week after not playing Sunday in the second half of the 24-20 loss to the New York Giants.

The Ravens (3-3) will rely on Kenyan Drake, who became the first Baltimore running back to produce 100 rushing yards this season, and a growing backfield for at least the next month. Justice Hill, who leads Ravens running backs with 6.6 yards per carry, is back for the game Sunday against the Cleveland Browns after missing the past two matchups with a hamstring injury. Gus Edwards could also be activated off the physically unable to perform list after practicing the past two weeks.

"Once you get him started and heading downhill, he's really effective," Ravens coach John Harbaugh said of Drake earlier this week. "He has some speed and some explosiveness."

This is another tough blow for Dobbins, who was sidelined all of last season after injuring the knee in the preseason finale. He said he tore the ACL, LCL, meniscus and hamstring.

After missing the first two games this season, Dobbins returned on a limited snap count and didn't look like he was at full strength. He had 123 yards on 35 carries in four games.

Last week, Dobbins acknowledged it was "super hard" not playing in the fourth quarter of the 19-17 win over the Cincinnati Bengals on Oct. 9. He then sat out the entire second half after hurting the knee Sunday at the Giants.

"J.K.'s knee tightened up on him," Harbaugh said earlier this week. "He just didn't feel like he had that explosiveness in the second half. I think he might've landed on it at some point."

A second-round draft pick in 2020, Dobbins was an immediate impact player, leading all NFL running backs in rushing average (6.0 YPC) and setting a Ravens rookie record with nine touchdowns.

This season, Baltimore running backs have totaled 458 rushing yards, 25th in the NFL.