SALT LAKE CITY — Isaiah Thomas, about to become a free agent under some particularly inopportune conditions, will have arthroscopic surgery today to repair a torn labrum in his hip, finally resolving a situation that began last season with the Celtics.

The Lakers guard, on his third team in a year, and traded from Cleveland to LA at the deadline after missing the first two months attempting to heal without surgery, originally suffered the injury as a Celtic last spring. He then played with the injury in the playoffs, later saying after his trade from the Celtics that he might not have played had he understood the severity of the injury.

“I don’t want to speak for him or his decision-making process,” Celts coach Brad Stevens said before last night’s game against Utah, “but obviously the most important thing for me is that he gets back healthy and fully healthy as quickly as possible. This sounds the right next step, and if that’s the decision he made, hopefully he gets back as soon as possible.”

Ex-Celts reunited

Jonas Jerebko and Jae Crowder have been reunited in Utah, and in terms of a playoff environment, both picked up where they finished last season as Celtics.

“I thought it was great,” said Jerebko. “Obviously we spent three seasons together in Boston so I knew what kind of player and person we’d be getting, so I knew he would fit in well. I knew he was a good teammate. We know he can do a little bit of everything on the court, so I knew he was going to fit in well with us. And as soon as it happened I called him and said let’s go.”

Speaking of his two former players, Stevens said, “Both those guys impact winning in a good way. They were really important parts of us in the way we played the last few years. Both bring great competitiveness, bring specific skills to the table in the way we want to play and the way the Jazz want to play.

“When that trade happened, I thought this was going to be a really good fit for Jae. Jonas, the same thing when he signed here last summer.”

Morris hobbled

This is admittedly the worst season of Marcus Morris’ career in terms of time lost to injury.

“My only year injury-wise,” the Celtics forward said yesterday. “It’s definitely tough, but you have to take care of your body. Do what you need to do to get back on the court.”

For Morris, getting back now won’t happen at the earliest until Saturday against conference-leading Toronto in the Garden, making him a definite scratch for last night’s game against the Jazz.

Morris aggravated a left ankle injury late in the third quarter of Monday’s win in Phoenix. Though an X-ray taken that night came back negative, Morris was still sore enough by yesterday morning to acknowledge he’s out for at least one more game.

“It’s about what I thought, just bruised. It’s up to myself on how I feel, but I’m thinking probably Saturday,” he said. “Not too bad. The swelling went down, just ice it a few times at night and day. It went down significantly. I’m just going off how I feel.”

Horford a no-go

Al Horford, who turned his left ankle in the first half of the Phoenix game, was ruled out last night. He waited to see how the ankle responded in the shootaround before making a decision.

“Obviously we want him to feel great,” said Stevens. “He tweaked it in the first half and was talking about it a little bit at halftime. He felt better in the second half, more sore yesterday.”

Guerschon Yabusele started for Horford. . . .

Guard Xavier Silas, the 30-year-old former Maine Red Claw who spent the last two years in the G-League, signed a 10-day contract with the Celtics yesterday.