LOS ANGELES (AP) — Star wide receiver Puka Nacua and cornerback Trent McDuffie are questionable to play in the Rams’ game at the Las Vegas Raiders on Sunday, while linebacker Nate Landman is out because of a concussion.

Nacua left practice early on Thursday because of a calf injury, but coach Sean McVay said there wasn’t an obvious cause or incident which precipitated his exit. Nacua’s availability will be a game-time decision.

“I don’t think he knows exactly when it occurred,” McVay said Friday. “Took part in a majority of practice, left, got it checked out, and so he’ll be questionable for the game.”

Nacua has 37 receptions for 417 yards and one touchdown in four games, having missed games against the New York Giants and Denver Broncos because of a hip and groin injury.

McDuffie (groin) was out for the Rams’ shocking 18-16 loss to the Arizona Cardinals on Sunday and had been arguably their best defender before that, posting 16 tackles with two tackles for loss, seven passes defended and one interception through five games.

Neither Nacua nor McDuffie participated in practice Friday.

Landman went into concussion protocol following the defeat to the Cardinals. He has 51 tackles with two tackles for loss through six games. He made 13 tackles and forced two fumbles in a 37-34 overtime loss to the Buffalo Bills on Oct. 12.

Veteran linebacker Eric Kendricks will be called up from the practice squad in Landman’s absence. Kendricks has played 11 seasons in the NFL, the bulk of them in Minnesota, followed by stints with the Chargers, Cowboys and 49ers over the past three seasons.

The Rams (2-4) are dealing with a major injury crisis following the loss to Arizona, with wide receiver Davante Adams out six to 10 weeks because of a hamstring injury which required surgery. Defensive tackle Kobie Turner is out for at least four games because of a groin injury which necessitated a stint on injured reserve, and defensive tackle Poona Ford is lost for the season because of a triceps injury.

If Nacua is out, Los Angeles’ wide receiver corps would consist of young reserves Konata Mumpfield and Jordan Whittington, undersized veteran Tutu Atwell, and rookie sixth-round pick CJ Daniels, who would be in line to make his NFL debut.

“I think it’s our job to figure out, all right, what are some of the spots that we can put them in that accentuate their skill sets,” McVay said. “Whether you’re talking about Davante, whether you’re talking about Puka, you don’t ever ask anybody to replace those guys.”

There could be some relief on the way, as McVay said it was a “possibility” pass rusher Myles Garrett could return to practice next week. Garrett, the Rams’ blockbuster offseason trade acquisition, underwent knee surgery and was placed on IR following his lackluster Week 1 showing in Melbourne, Australia.