Oklahoma City Thunder star Jalen Williams will need to undergo surgery for a fractured fibula and dislocated left ankle, OKC general manager Sam Presti said Monday. An exact return timeline won't be known until after surgery, Presti said, but ESPN reported that it could be a season-ending injury. Presti disclosed Monday that Thunder guard Cason Wallace will also need surgery. Wallace hurt his shoulder against the Clippers on Sunday and will undergo a procedure to repair a torn labrum. Wallace, too, could be out for the season, per ESPN, but the Thunder had no official timeline on his potential return.

"Tough night last night. There's no way to paint that differently," Presti told reporters.

Williams was taken off the court on a stretcher late in the fourth quarter of a 108-101 win over the Los Angeles Clippers on Sunday night after suffering the severe lower leg injury. 

With just over a minute to play, Williams drove to the basket and tried to go up for a dunk. He was sandwiched in mid-air by Kris Dunn and Derrick Jones Jr., which caused him to lose his balance. When he landed, his left leg got trapped underneath the weight of his entire body and the lower part of it appeared to break in the wrong direction. 

The Thunder training staff immediately covered his leg with towels as his teammates looked on in distress. Shai Gilgeous-Alexander pulled his own jersey up over his face as Williams' leg was placed into an air cast and he was loaded onto a stretcher. 

"I just feel bad for him. Nothing more than that," Gilgeous-Alexander said on the court after the win. 

Thunder coach Mark Daigneault said the team had no immediate update on Williams' status. 

"We're not doing great," Daigneault said. "That's tough on the guys." 

Williams gave the crowd a thumbs-up as he was wheeled off the court.

Williams was coming off season derailed by injuries

Williams, 25, emerged as a true star in 2025, when he made his first All-Star appearance and earned a spot on the All-NBA Third Team and the All-Defensive Second Team before helping Gilgeous-Alexander lead the Thunder to their first title since moving to Oklahoma City. Williams averaged 23.6 points in the 2025 Finals and had a playoff-career-high 40 points to lead the Thunder to a Game 5 win that gave them a 3-2 series lead over the Pacers (OKC won in seven games). 

He played through a wrist injury during the 2025 playoffs, however, and underwent surgery last summer to fix the problem, which kept him sidelined for the first 19 games of last season. Less than two months into his return, he strained his right hamstring and was sidelined for multiple weeks. He came back, played two games, then tweaked his hamstring again and missed another six weeks. 

Williams returned shortly before the playoffs last season, but suffered a left hamstring strain in Game 2 of the Thunder's first-round series with the Phoenix Suns. He sat out the rest of that series and missed the entire second round before coming back for the Western Conference Finals against the Spurs. After a stellar Game 1, he tweaked his left hamstring again in Game 2 and only played 10 more minutes the rest of the series. 

When the Thunder lost Game 7 to the Spurs, which ended their repeat quest, he was forced to watch from the bench in street clothes. 

What Jalen Williams and Cason Wallace injuries mean for the Thunder and why a trade isn't so simple
Sam Quinn
What Jalen Williams and Cason Wallace injuries mean for the Thunder and why a trade isn't so simple

Williams and Wallace injuries a major blow to OKC's title chances

The Thunder made some moves around the margins this offseason -- most notably, trading Lu Dort to the Atlanta Hawks -- but brought back their entire core and hoped to make another run at the title in a top-heavy Western Conference. Vegas oddsmakers installed them as the preseason favorite to win the title, and they started the season with a convincing win over the Spurs. 

Though he was off to a somewhat slow start, Williams was averaging 13.7 points, 4.7 rebounds, 3.3 assists and one steal to begin the season, and was second on the team in scoring behind Gilgeous-Alexander. CBS Sports ranked Williams as the 20th-best player in the NBA in the annual Top 100 player rankings. 

Sunday's win over the Clippers moved the Thunder to 3-0, and even without Dort, they have the depth to withstand Williams' absence -- at least in the regular season. They won 64 games last season largely without Williams. But it will be tougher to withstand Williams' absence with Wallace joining him on the bench.

A fourth-year guard, Wallace had worked his way into the OKC starting lineup. He made All-Defense Second Team last season while averaging 8.6 points per game. His emergence was one of the reasons why the Thunder felt comfortable trading away a veteran like Dort. Wallace had started in all three games this season before the injury.

Williams' injury draws comparisons to Hayward's

The gruesome nature of Williams' injury and the reactions it elicited from teammates reminded fans of Gordon Hayward's injury nine years ago.

Hayward, like Williams, dislocated his left ankle and fractured his left tibia on opening night of the 2017-18 season in his debut with the Celtics. He missed the remainder of that season and was never the same player. Hayward appeared in 318 more games over six seasons before retiring at 33 years old.