Jimmy Butler suffered a knee injury during Wednesday night's 105-104 loss to the Philadelphia 76ers in the Play-In Tournament.

The veteran forward—who finished with 19 points, five assists, five steals and four rebounds but shot just 5-of-18 from the field—told reporters after the game that he would undergo an MRI on Thursday.

"It had me feeling that I couldn't do too much," the Miami Heat star said of the injury.

The Athletic and Stadium's Shams Charania reported after the game that Butler "is feared to have an MCL injury in his knee" that could sideline him "for an indefinite period."

The 34-year-old was seen exiting Wells Fargo Center limping:

Butler was injured in the first quarter while going up for a layup. Philly's Kelly Oubre Jr. bit on a pump fake and landed on him, coming down on his leg:

Butler didn't leave the game and played 40 minutes in total, but head coach Erik Spoelstra told reporters that the injury got worse as the game progressed:

Any chance the Heat have of advancing out of the Play-In Tournament—and perhaps pulling an upset of the Boston Celtics in the first round of the Eastern Conference playoffs, or making a deep run after that—will hinge on Butler's health.

Behind the star wing, the Heat have reached the NBA Finals in two of the past four seasons and the Eastern Conference Finals in three of those campaigns, though a title has eluded them.

Butler seems to turn up his game in the postseason, especially in the past two years. During the 2021-22 postseason, he averaged 27.4 points per game. In last year's playoffs, he put up 26.9 points per contest. He has never averaged more than 23.9 points per game during the regular season.

Miami, in general, seems to hit a different gear in the postseason. But the Heat may not even qualify for this year's playoffs if Butler's injury is indeed as serious as feared.