Tight end Nick Boyle has passed the concussion protocol, but it's not clear yet whether he will be available for Saturday night's game in Los Angeles.
Boyle left Sunday's game against the Tampa Bay Buccaneers early. He returned to practice Thursday before the team departed for L.A. and is listed as questionable.
"He's progressing well. We'll just have to see," Harbaugh said. "I think it'll be a little bit of a decision on Saturday, maybe today, to see how he gets through the practice and everything, see how he feels."
Getting Boyle back on the field would be a boost to Baltimore's rushing attack, as he's the team's best blocking tight end. Boyle would likely be helping to block talented Chargers defensive ends Joey Bosa and Melvin Ingram.
Maxx Williams and rookies Hayden Hurst and Mark Andrews filled in well after Boyle went down, but the Ravens would rather have all four of their tight ends.
Alex Lewis Brings Another Wrinkle to O-Line
Left guard Alex Lewis (shoulder) practiced fully throughout the week and is also listed as questionable to play in Saturday's game after missing the last two contests.
James Hurst started the Ravens' Week 14 game in Kansas City, and he and rookie Bradley Bozeman shared the job last Sunday against Tampa Bay.
If Lewis is ready to play, it throws into question whether he will be inserted back into the starting role, share the job or be the team's reserve sixth lineman.
Matthew Judon Improves During the Week
Outside linebacker Matthew Judon left Sunday's win over the Bucs briefly because of a knee injury, and the Ravens held him out of Tuesday's walk-through.
He has improved throughout the week, however, and was a full practice participant Friday. Judon is questionable to play.
Linebacker/defensive back Anthony Levine (toe/ankle) is also questionable.
Chargers' Melvin Gordon Will Play, Keenan Allen Expected to as Well
It looks like the Chargers will have their full arsenal of weapons against the Ravens, as two of their biggest stars are expected to suit up.
Running back Melvin Gordon will play, as he's not on the Chargers' final injury report. He practiced fully all week after missing the past three games because of a knee injury. One of the league leaders in yards per carry (5.2) and total yards, Gordon is a major, dynamic weapon.
"Melvin's practiced all week and he's doing fine," Chargers Head Coach Anthony Lynn told SiriusXM's Ross Tucker. "I don't know that he's himself, but he's going to play."
Wide receiver Keenan Allen suffered a hip injury early in last Thursday's game against the Chiefs, but with the long week to recover, he's reportedly recovered. The Chargers' No. 1 receiver (1,074 yards) was limited on Wednesday and Thursday, and is officially questionable.
Backup running back Austin Ekeler (concussion) is doubtful, but Justin Jackson has done well filling in.