According to Harbaugh, who is on vacation, the two have plans to meet soon to discuss the future of Baltimore's leading receiver.
"We have an appointment to talk real soon, either by phone or when I get back next week," Harbaugh said Wednesday via conference call. "It'll be interesting to see where he's at with everything. I know he's gone through a lot in the last couple weeks with Steve's [McNair] situation and those kinds of things. But I'm looking forward to talking to him."
Harbaugh said he took the news of Mason's announcement, which first appeared Monday on a Web site registered to his agent, C. Lamont Smith, in stride when it caught much of the NFL world by surprise.
There has been much speculation as to why Mason did, in fact, make his decision.
McNair, one of Mason's closest friends, was shot and killed on July 4, and Mason spoke at a memorial service honoring the former Ravens and Tennessee Titans quarterback in Nashville.
Mason, 35, also is attempting to recover from a shoulder injury that required offseason surgery.
But even as Mason denies that money is an issue, he did publicly lobby for a contract extension earlier in the offseason.
"I have been thinking about this since the season ended," Mason said in a statement. "Emotionally I am just not that enthused. I have not been that enthused to get up and work out…it was getting to that point. This decision has nothing to do with the contract situation; I have made enough money, more than enough money. Emotionally there are things that are more important. It's time right now.
"I don't know what's going to happen from here, but it's going to be really nice to see what life has in store for me."
The next step for Harbaugh and the Ravens is to identify if Mason will be in a Ravens uniform next year.
If not, the contingency plans include keeping the roster as it currently stands, trade for a marquee receiver or add a veteran free agent.
"We know who's out there at every single position, and we're always working the roster," Harbaugh noted. "So, obviously if Derrick does retire, that's going to perk us up even more as far as strengthening that position like we will any position. But, you can only do so much. There are only so many guys out there available, and a lot of what we do is developing the players that we have. We think we have good players here, too.
"I just think there's a lot of time to go between now and when training camp starts, and of course between now and when the season starts. Derrick Mason is a warrior, he's a tremendous family man, he has good relationships with everybody inside the building. I'm just looking forward to seeing how this goes."