No, Harbaugh didn't provide a definitive forecast, but he weighed in with his opinion about whether Lewis will play again this season.
"I think he will. That's a best guess," Harbaugh said. "He's working hard to do that."
Lewis had been placed on injured reserve as "designated to return," a new NFL rule that makes it so teams can choose one injured player to go on the IR and be eligible to come back later in the season.
When Lewis tore his right triceps against the Cowboys on Oct. 14 and then had to undergo surgery to repair it, it was believed he'd be done for the year.
Now, the star linebacker is eligible to return to practice this week and Harbaugh said there's "a possibility" that the Ravens' leader will be able to do so when rules allow it.
Harbaugh indicated he'll have a better idea whether it's realistic to say Lewis could play again this year after seeing him in action.
"We'll know then. We'll have to test it and see if it can hold up," Harbaugh said. "We really don't know where it's at right now. Ray has been in rehab mode, so he hasn't been here from a football standpoint in terms of us seeing into that yet. But just talking to Ray, it sounds like things have gone well. There have been no setbacks, so there's a possibility."
Harbaugh was also asked about whether there is urgency to rush Lewis back, as there might've been with linebacker Terrell Suggs, who returned from a torn Achilles tendon in less than six months. At the time of Suggs' return, the Ravens' defense was struggling badly and had just lost Lewis and cornerback Lardarius Webb to long-term injuries.
At this point, the Ravens' defense is improving, allowing 309 yards or fewer in three of the last four games, and the team has won four in a row to improve to 9-2.
"Well, I think it'd be great to get Ray Lewis back. All of our guys would welcome Ray back with open arms if and when that happens," Harbaugh said. "It's just Ray is part of our defense, just like Terrell Suggs is part of our defense. So the whole thing is coming together hopefully better every week, and hey, we could stumble at any time in this league. But adding a great player into the mix is only going to make us better."
It's been a fascinating year for the Ravens health-wise, and if Lewis is able to make it back from torn triceps in a matter of months, that'll make it two medical miracles when coupled with Suggs' return.
"We'll see about Ray, first of all. That has yet to play itself out," Harbaugh cautioned. "I just have so much confidence in who Ray is as a person and a man, and the same thing for Terrell Suggs.
"These guys are physically, genetic, special DNA type guys ... and they work harder than anybody in this (press) room, physically. That's for sure. So give credit where credit's due and then we'll just see how Ray does. But I know one thing - he's working harder than any of us can imagine to try and get back and healthy."