The fourth-year RB will miss the remainder of the 2023 season.
"I'm crestfallen for him," Harbaugh said, per ESPN's Jamison Hensley. "We'll put our arms around him and he will be back."
Dobbins came up hobbling after getting tackled as he fought toward the end zone after receiving a short pass from Ravens quarterback Lamar Jackson. Initially going to the sideline under his own power, Dobbins had to be helped by trainers as he went to the locker room.
Justice Hill scored on a 2-yard run the very next play, extending the Ravens' lead, 13-6, early in the third quarter.
Baltimore later announced Dobbins was out for the game with an ankle injury.
Dobbins, who scored the game's first touchdown on a 4-yard run in the first quarter, totaled eight carries for 22 yards and two catches for 15 yards.
A torn Achilles is a crushing blow for a player who had worked his way back from a serious knee injury that held him out of the 2021 season entirely. The injury is compounded by the fact that Dobbins and the Ravens were unable to come to an agreement on a potential contract extension this offseason. Dobbins is set to make $1.39 million in base salary this season -- the final year of his rookie deal.
Dobbins, a second-round pick in 2020, has averaged 5.9 yards per carry in 23 career games with 12 total touchdowns.
The Ravens' defense also has a potential long-term injury to deal with following the 2023 season opener.
Rapoport reports Ravens defensive back Marcus Williams is feared to have suffered a torn pec in Sunday's win, per a source. Williams is set to have an MRI to confirm the severity of his injury.
Williams was ruled out of the game in the second half after suffering the injury.