While Harbaugh also said that there has been no definitive word, he acknowledged that the early indications have provided at least some hope that the reigning NFL Defensive Player of the Year may not be out for long.
"I think we are encouraged that it may not be [long-term]," Harbaugh said. "We'll just have to see. If I knew that for sure, if I could say that for sure, I would. I just can't right now but we have some encouragement there."
Losing Suggs for any length of time would be another blow to the Ravens' defense which couldn't hold a 13-3 lead Sunday and allowed a Charlie Batch-led offense to wrack up 366 total yards. Batch, the Steelers' third-string quarterback who turns 38 on Wednesday, completed 25-of-36 passes for 276 yards, one touchdown and one interception.
Batch hit tight end Heath Miller on a 7-yard touchdown to tie the game at 20 with 7:24 left in the fourth quarter and then he led a 12-play, 61-yard drive that resulted in Shaun Suisham's game-winning, 42-yard field goal as time expired.
Before his injury, Suggs had two tackles in the game, including one for a loss, but like his teammates, he wasn't able to apply consistent pressure on Batch who was sacked only twice in 36 dropbacks.
In six games, Suggs, who the team feared was done for the season when he had Achilles surgery in May, had 19 total tackles, two sacks and four passes defended. Along with upgrading the Ravens' run defense with his ability to set the edge, Suggs, even while working his way back in shape and clearly lacking his normal explosiveness, has provided a defensive presence for a unit that has struggled for much of the season.
Asked about the impact of Suggs' potential loss, McPhee said Sunday, "We just got to man up. We've been fighting injuries all year."
The Ravens already are playing without inside linebackers Lewis and Dannell Ellerbe, along with cornerbacks Lardarius Webb and Jimmy Smith. Webb (anterior cruciate ligament and meniscus tear in left knee) is only one who is certain to be out for the rest of the season.
Lewis, whose quick return from the triceps injury mirrored Suggs' surprising comeback, potentially could practice this week but isn't eligible to play in a game until Dec. 16 against the Denver Broncos.
Ellerbe, one of the team's top tacklers who is dealing with injuries to his ankle, foot and both of his thumbs, missed Sunday's game and acknowledged that he wasn't particularly close to playing. However, Harbaugh said Monday that he's hopeful of getting him back against the Redskins.
Smith had surgery on a sports hernia about 2 1/2 weeks ago and Harbaugh said that he's making steady progress though he isn't expected to be ready by this weekend.
Baltimore Sun reporter Aaron Wilson and columnist Mike Preston contributed to this article.