Of the many injuries the Los Angeles Rams suffered Sunday night against the Detroit Lions, that of Puka Nacua is certainly the most concerning. The star receiver left the game in the second quarter after injuring his knee, and though he returned for one play, he left the game again and was ruled out.

It’s the same knee he injured this summer during a joint practice with the Chargers, though he appeared to have fully recovered. Sean McVay had no update on Nacua following the overtime loss, but the receiver will not undergo any further testing on Monday, according to NFL Network’s Ian Rapoport.

“He’s going to have tests this afternoon to determine what’s going on with his knee,” Rapoport said. “There’s no definitive word on his status yet, but it’s clear he’s got the same knee he had during training camp, there’s clearly an issue, he’s clearly had some pain that he’s been struggling with. He wouldn’t be surprised if he misses some time to figure it out and try to improve that issue.”

Nacua missed a few weeks of training camp due to his first knee injury, a ruptured bursa.

This article originally appeared on Rams Wire: Puka Nacua to undergo tests on injured knee on Monday