Harbaugh, who is on vacation, said he has exchanged text messages with Mason since the team's leading receiver decided to retire Monday.
"We have an appointment to talk real soon," Harbaugh said Wednesday. "It will be interesting to see where he's at with everything. I know he's been going through a lot the last couple of weeks with Steve's [McNair] situation, but I'm looking forward to talking to him."
A team source told The Baltimore Sun that Mason's decision might have been motivated by a family situation.
There has been speculation all week that Mason might be trying to use this announcement to gain leverage in talks for a contract extension. Mason, 35, who is not speaking to the media for the next two weeks, told ESPN on Monday that he didn't think the Ravens could do anything financially to change his mind.
"If I do change my mind ... it'll be because of some other things - my family and talking with other people," said Mason, who is married with two children.
There's no sense of urgency from the Ravens to replace Mason immediately.
The team could look to add a free agent (such as Marvin Harrison) or explore a trade (for someone like the Denver Broncos' Brandon Marshall or Arizona Cardinals' Anquan Boldin). By signing linebacker Terrell Suggs to a long-term deal Wednesday, the Ravens put themselves $7 million under the salary cap. If Mason retires, the team's cap room would increase to $10 million.
"Obviously, if Derrick decides to retire, it's going to perk us up even more as far as strengthening that position," Harbaugh said. "But you can only do so much. There are only so many guys out there available, and a lot of what we do is develop the players that we have. I think there is a lot of time between now and when training camp starts.
"Derrick Mason is a warrior and a tremendous family man. He's got a good relationship with everybody inside the building. I'm looking forward to see how it goes."
Mason has had an emotional couple of weeks. McNair, his longtime friend and teammate, was shot and killed July 4. Last Thursday, Mason spoke at McNair's memorial service.
Harbaugh said he wouldn't have any concerns with Mason's mindset if he decides to come back.
"I know if he decides to come back, he'll be completely and totally ready to go," Harbaugh said. "If not, we'll move on as a football team."