Nacua went to the locker room favoring his right shoulder during Sunday's game versus the Browns, Adam Grosbard of The Orange County Register reports.
Nacua initially was questionable to return in the middle of the second quarter due to cramps, but he was able to return, only to endure a hard landing on a leaping 20-yard grab. He stayed on the turf for some time before making his way to the sideline slowly with Rams trainers. If he's unable to return, Nacua will finish Week 13 with four catches (on six targets) for 105 yards and one touchdown on the strength of a 70-yard TD.