Boston Celtics centre Kristaps Porzingis sustained a rare injury to his left leg, putting his status for Game 3 of the NBA Finals on Wednesday into question.

The Celtics announced on Tuesday that he suffered a torn medial retinaculum allowing dislocation of the posterior tibialis tendon.

The injury occurred with 3:27 to play in the third quarter of Sunday's 105-98 win over the Mavericks, which gave Boston a 2-0 lead.

The team described the injury as being rare, and said it is unrelated to a right calf strain that side-lined Porzingis for 10 games earlier in the play-offs.

He has not yet been listed on the official injury report, but the Celtics said his status is day to day.

Celtics coach Joe Mazzulla told reporters that Porzingis is working hard to be ready to play.

“It's a serious injury," Mazzulla said. "At the end of the day, our medical team is not going to put him in any bad situations. So, we’ve taken the decision to play out of his hands.”

Porzingis was seen wearing a brace before speaking with the media on Tuesday.

"I'll see how I am tomorrow," he said, "and obviously I'm going to do everything I can to be out there."

Porzingis helped spark the Celtics in Thursday's 107-89 win in Game 1, tallying 11 points and two blocks in the first quarter in his first game since April 29.

He finished with 20 points on 8-of-13 shooting and six rebounds before recording 12 points and four boards in Game 2.