The news was earlier reported by ESPN.com's Pierre LeBrun.
"Tim came to me via his agent toward the beginning of May and said he was thinking of taking the year off," Chiarelli said in a conference call Friday. "The reasons are ... I'm not exactly sure, but he did give reasons why regarding the family, which obviously I respect."
On Sunday, Thomas wrote about his concerns on his Facebook page but did not confirm a decision.
"At the age of 38, I believe it is time to put my time and energies into those areas and relationships that I have neglected," Thomas wrote. "That is why at this time I feel the most important thing I can do in my life is to reconnect with the three F's. Friends, Family, and Faith."
Chiarelli said Thomas, 38, hasn't indicated when he will make a final decision. As a result, Chiarelli must proceed as if the two-time Vezina Trophy winner won't be with the team in 2012-13.
"I almost have to operate under the assumption he isn't coming back," Chiarelli said Friday. "I've had some discussions with Tim and he's told me that he wants to play in the Olympics the following year, so I'll have more discussions with him later on. But we've got two very capable goalies in [Tuukka] Rask and [Anton] Khudobin, so I'd be more than satisfied if that's who we have to go with."
Rask is a restricted free agent and still unsigned. Khudobin has one year left on a one-way deal. The Bruins also signed goalie Niklas Svedberg to an entry-level deal earlier this week.
Chiarelli would not comment on negotiations with Rask except that the Bruins intend to sign him. When asked if he would consider signing a veteran free-agent goalie, the GM reiterated he's happy with the goaltenders currently on the roster.
Thomas is entering the final season of a contract that will pay him $3 million and will cost the Bruins $5 million against the cap. Chiarelli said if Thomas hasn't made a definitive decision on whether he will play by the beginning of next season, he would suspend the goalie.
But even if the Bruins suspend Thomas, the cap hit still would count against the team for next season. However, the Bruins would gain $4 million of that back by placing injured center Marc Savard on long-term injury reserve.
"If he wasn't playing I would have to suspend him," Chiarelli said of Thomas. "His cap number would still be on the cap. We would have relief through Savard being on the cap, so it would almost be a wash that way, and that's the way we would proceed through the year. We're not seriously cramped from the cap perspective. As I've said, we've got Marc Savard on LTI and he's at $4 million, and Tim's at $5 million, so do the math and we're maybe a million short. So we're not seriously disabled there. It's something that I'll approach delicately with Tim."
If Thomas is suspended, Chiarelli also has the option to toll the contract into 2013-14. The team would maintain Thomas' services with the same $5 million cap hit, but Chiarelli stressed that no matter what, the cap hit remains for the upcoming season.
"I would be able to toll the contract, which would mean I would acquire the same terms of service in a subsequent year," Chiarelli said. "I would have the ability to decide if I want the contract to expire or for it to go another year."
Chiarelli plans on giving Thomas some time to make a final decision, possibly until July 1, when the 2011 Vezina Trophy and Conn Smythe Trophy winner's no-movement clause expires. At that point, the GM would explore trade and transaction options to alleviate Thomas' cap hit and get some value in a potential trade.
"That would be something we'd look at and you do have that flexibility and the element of teams trying to reach the [cap] floor -- I don't know what that would be in the next CBA deal, so there's uncertainty there, too -- but yeah, that would be something we'd look at," Chiarelli said.
Chiarelli acknowledged Thomas' potential decision to sit -- regardless of whether he follows through with it -- has diminished the goalie's trade value; many teams are unlikely to part with a quality package in exchange for a 38-year-old goalie who most likely is forgoing the final year of his contract with no guarantee he'll return.
But while some have speculated that Thomas may make this decision to decrease his trade value so that he would not be able to be dealt to whichever team the Bruins wanted, Chiarelli did not sense that from Thomas and his agent, Bill Zito.
"No, and I asked Bill that question, and no," Chiarelli said. "I don't think there's anything mischievous from his part. I really felt it's what he said that he wanted to take a break, and I've seen this happen with players -- maybe not as definitive as Tim -- but after long stretches at particular points in their careers they say, 'I gotta take some time before I decide I want to come back,' and Tim has said he's not, but people change their minds also."
So Chiarelli now will move on and try to make the best out of this peculiar situation.
"I'm a little ... well a little more than a little, I'm disappointed," Chiarelli said. "But these things happen, and you gotta roll with them. You got to deal with them, and when someone talks about their family and stuff, you have to respect that. We're not too disabled on the cap side and that was a strength of our team, but this happens as years progress and players take over certain roles, and that's what happened here."