Jayson Tatum suffered a ruptured right Achilles tendon during the Boston Celtics' playoff defeat to the New York Knicks, the NBA champions confirmed, leaving the basketball superstar facing a lengthy spell on the sidelines.

"Jayson Tatum today underwent successful surgery to repair a ruptured right Achilles tendon," the Celtics announced on X, formerly Twitter. "No timetable is currently available for his return, but he is expected to make a full recovery. Further updates will be provided when appropriate."

Tatum was carried off the court in the fourth quarter of Boston's 121-113 loss on Monday that leaves them on the brink of elimination from the postseason.

Tatum, a six-time NBA All-Star and a member of the USA's Olympic gold medal-winning teams at the Tokyo and Paris Games, had crumpled to the floor at Madison Square Garden in agony on Monday after suffering the injury. Tatum had been in superb form before the injury, scoring 42 points in a classic duel.

He was helped off the court and was later ferried to the locker room in a wheelchair, the evident seriousness of the injury drawing an outpouring of support and concern from teammates and fellow players from across the NBA.

"Hate that it happened. The NBA is a brotherhood, praying for him," Knicks star Josh Hart said during a post-game interview.

LeBron James also posted a message of support on X, while stars from other sports also extended sympathy.

Tatum's injury complicates the Celtics' efforts to dig themselves out of their 3-1 hole against the Knicks, who can clinch the best-of-seven series with victory in Boston on Wednesday.

It also casts a pall over the team's future, with serious Achilles injuries often involving a recovery time of up to a year or more.

NBA great Kevin Durant was out for roughly 18 months after tearing an Achilles tendon during the 2019 NBA Finals. Durant missed the entirety of the 2019-2020 season, finally returning in December 2020.

The Dallas Mavericks' Klay Thompson also suffered a lengthy layoff following a torn Achilles. Thompson, who was with the Golden State Warriors at the time, suffered an Achilles tear in November 2020 and did not return until January 2022. (AFP)