DALLAS – Boston Celtics center Kristaps Porzingis has what the team has called a “rare injury” to his left leg that leaves him day to day for the rest of the NBA Finals.

Porzingis sustained a “torn medial retinaculum allowing dislocation of the posterior tibialis tendon” in Boston’s 105-98 victory against Dallas in Game 2 Sunday. He is listed as questionable for Game 3 Wednesday (8:30 p.m. ET, ABC).

Celtics coach Joe Mazzulla called it a serious injury and said Porzingis is “doing anything and everything he can to be able to play, adding, "At the end of the day, our team and the medical team is not going to put him in any bad situations. We've taken the decision to play out of his hands because the importance of him. He's going to do everything can he to play. We're going to leave it up to our medical team."

Said Porzingis: “I’ll see how I am (Wednesday). Obviously, I’ll do whatever I can to be out there, and we’ll see.”

The injury happened with 3:27 left in the third quarter when he tangled with Dallas' Dereck Lively II and Jaden Harden on Jaylen Brown's free throw attempt.

Certified athletic trainer Jeff Stotts, who maintains a comprehensive database of NBA injuries, posted on social media that he has just one other incident of a similar injury in his database.

“If the retinaculum is torn, the tendon can slip out of place, causing pain and instability of the ankle and foot,” Stotts posted.

Porzingis has had multiple foot and ankle injuries and just returned to the playoffs for Game 1 of the NBA Finals, after missing more nearly six weeks with a right calf injury. He had 20 points, six rebounds and three blocks in Game 1 and 12 points and four rebounds in Game 2.

What is the posterior tibialis tendon?

A posterior tibial tendon, according to the Cleveland Clinic, “connects your calf muscle to bones on the inside of your foot. The main purpose of the tendon is to support the arch on the inside of your foot. When the tendon is injured or breaks down, it may no longer be able to support the arch. It can be a painful injury that negatively affects foot and ankle movements, including walking and running.”

A dislocated posterior tibialis dislocation is considered rare and painful.

What is a retinaculum?

According Stotts, the retinaculum is a “connective tissue that serves as the roof of the tarsal tunnel (think carpal tunnel but in the foot). It anchors multiple structures in place, including the tendon of the posterior tibialis.”

How is a disclocated posterior tibialis tendon treated?

Surgery is an option, but Porzingis isn't taking that option, at least now. Rest, ice, medicine, physical therapy and orthotics are common treatments, according to the Cleveland Clinic.

Will Kristaps Porzingis play in Game 3 of NBA Finals?

Porzingis' status is unclear. He's questionable, says he's optimistic but the Celtics' medical staff will make the final call.

"Nothing is going to stop me unless I'm told I'm not allowed to play," Porzingis said. "That's the only reason I would not be out there."

Playing is possible "if his associated symptoms are manageable and the medical team is able to stabilize the tendon," Stotts wrote in a blog post. "However, the risk of further injury will linger especially with Porzingis' lengthy lower extremity injury history."

This article originally appeared on USA TODAY: Celtics' Kristaps Porzingis suffers rare left leg injury in NBA Finals