Dobbins, who tore his left ACL last August, has been participating in individual drills for five days since being activated off the physically unable to perform list. The Ravens remain non-committal on if Dobbins will be recovered enough to play Sept. 11 at the New York Jets.
"He's made some good progress this week," Harbaugh said after Wednesday's practice. "We measure times of how fast he runs, how fast he decelerates, how fast he changes direction. You can see the improvement is tangible. So, we'll see."
Dobbins, a second-round pick in 2020, led all Baltimore running backs in rushing yards (805) and touchdowns (nine) as a rookie. Last year, he suffered a season-ending knee injury in the opening series of the preseason finale.
In terms of recovery, Dobbins has been ahead of running back Gus Edwards, who had a season-ending knee injury last September. Edwards, the team's No. 2 running back, remains on the PUP list.
If Dobbins isn't ready by the start of the regular season, the Ravens will lean heavily on veteran Mike Davis, who was signed this offseason. Last year, Davis ran for 503 yards and three touchdowns for the Atlanta Falcons.
Since Dobbins suffered that injury, Baltimore has been more cautious in playing its top players in the preseason. Quarterback Lamar Jackson and tight end Mark Andrews both will not play Sunday in Arizona, according to Harbaugh. Jackson and Andrews were also held out of last week's preseason opener.
In other injury news, Harbaugh said first-round pick Tyler Linderbaum is scheduled to return to practice Friday. The rookie center injured his left foot on Aug. 5.
"I don't anticipate him playing in the game," Harbaugh said. "But he'll start working his way back in."