Puka Nacua left Sunday’s game between the Los Angeles Rams and Detroit Lions due to a knee injury.

The Los Angeles Rams receiver appeared to sustain the injury in the first half. He returned briefly but then left the game to meet with medical trainers. Nakua was able to run down the sideline but left the game on the cart.

The Rams announced after halftime that he would not return to the game.

Further details about Nacua’s injury were not immediately clear. The Lions led 10-3 at halftime.

Nacua, 23, was one of the biggest surprises of the 2023 season. A fifth-round rookie out of BYU, Nacua developed into the Rams’ No. 1 receiver and one of the most productive receivers of the NFL last season, finishing the season with 105 catches for 1,486 yards and six touchdowns, earning him a Pro Bowl selection.

With Nacua alongside a healthy Cooper Kupp after two injury-plagued seasons, the Rams entered 2024 with one of the NFL’s most promising wide receiver duos. A long-term injury would be a major blow to the Rams’ offense as they look to compete for their fourth playoff berth in five seasons.