Mark Ingram II (calf) returned to practice Thursday, but his status for Saturday night's playoff game remains uncertain.
"He was limited participation," Harbaugh said after practice. "That's the definition of it. We'll see how it goes."
Ingram suffered his injury Dec. 22 against the Cleveland Browns and he did not play Week 17, nor did he participate in practice Tuesday or Wednesday.
Last week, Ingram said he expected to play in the playoff opener and his return to the field Thursday was a positive step. He did some light running on the sideline during the portion of Thursday's practice that was open to the media.
Ingram was named to the Pro Bowl for the third time in his career after rushing for 1,018 yards and averaging 5.0 yards per carry.
If he is not available or limited Saturday night, Gus Edwards would take over as the primary running back with rookie Justice Hill in the rotation. Edwards ran for a career-high 130 yards against a strong Pittsburgh Steelers defense in Week 17, even though Pro Bowl linemen Ronnie Stanley and Marshal Yanda were not in action. Hill has scored touchdowns in back-to-back games.
The Ravens had the No. 1 rushing offense in the NFL this season, setting a single-season team record (3,296 yards), while Lamar Jackson also set the single-season record for most rushing yards by a quarterback (1,206 yards).