Jayson Tatum left the Boston Celtics’ Monday night victory over the Sacramento Kings early after suffering a left ankle sprain in the third quarter, but the four-time All-NBA forward expressed optimism after the win that the injury wouldn’t prove to be as bad as it first looked.

Tatum, who sits sixth in the NBA in scoring, had already racked up 21 points to pace the Celtics as he received a pass from Derrick White with just under four minutes to go in the third quarter at Golden 1 Center. A ball screen from Kristaps Porziņġis prompted Kings center Domantas Sabonis to switch onto Tatum above the 3-point arc — a tasty mismatch for Tatum to attack. After a rhythm dribble, Tatum side-stepped to his left and launched a 3-pointer; Sabonis, eager to contest the shot but a bit late in doing so, wound up too close for comfort.

As the shot splashed through the net, Tatum’s left foot landed on top of Sabonis’, leading to a nasty roll that left the Celtics star on the sideline in a heap, grasping for his left foot in clear and obvious pain:

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Trainers and teammates surrounded Tatum on the sideline as the officials went to the monitors to review the play, eventually elevating the penalty against Sabonis from a common defensive foul to a flagrant foul-1 for stepping under an airborne shooter. Tatum would eventually be helped to the Boston bench, taking a couple of minutes to gather himself before returning to shoot two free throws for the flagrant; he split the pair and immediately checked out, ending his night with 25 points, seven rebounds and eight assists in 27 minutes.

The Celtics led by 11 when Tatum checked out, and would push the advantage as high as 22 in what settled as a 113-95 road victory. Sixth Man of the Year candidate Payton Pritchard scored 22 points and made five 3-pointers off the bench, while White chipped in 12 points, eight assists, five rebounds and a pair of steals for the defending NBA champions, who have now won six straight, 11 of their last 12 and 17 of 20 to improve to 53-19 on the season — Boston’s fourth consecutive 50-win campaign.

Sabonis, who just recently returned from a nasty ankle sprain of his own suffered after landing on a defender’s foot, expressed remorse after the game.

“I feel horrible,” he told reporters. “I’ve had a crazy month myself, personally, and you never want that to happen. So, I apologize.”

Adam Himmelsbach of The Boston Globe reported that Tatum “was not wearing a boot or using crutches” in the visiting locker room, and that, “when he eventually left to board the team bus, he hardly showed any signs of a limp.” After the game, Tatum told ESPN’s Ramona Shelburne that his ankle is “just sore,” but did say that the team is “going to be cautious.”

There’s no such thing as a good time to lose someone like Tatum, who leads the Celtics in scoring, rebounding and assists, grades out as a top-five player in a slew of advanced metrics, and has long served as the do-it-all two-way linchpin of a Boston squad that mauls through malleability. If the 27-year-old needs some time to recuperate, though, this isn’t too bad a spot in the calendar for it.

Boston’s all but locked into the No. 2 seed in the East, sitting 4.5 games behind the conference-leading Cavaliers and owning an eight-game cushion on the third-place Knicks. Monday marked Tatum’s 66th appearance of the season, too, so he’s already past the 65-game threshold for year-end awards eligibility, all but ensuring that a fourth straight All-NBA First Team selection — and potentially another top-five finish in MVP voting — will soon come his way.

Hitting the postseason healthy is the most important priority for a Celtics team looking to defend its title. If the training staff decides discretion is the better part of valor, Boston should have more than enough firepower to withstand a few games without Tatum; if he shows up for Wednesday’s meeting with the Suns feeling fully operational and ready to rock, then so much the better.

“I literally just asked him how he was doing and he said, ‘OK,’” Celtics coach Joe Mazzulla told reporters after the game. “He’ll do anything and everything to make sure he gets better.”