LOS ANGELES — Nelson Spruce’s injury frustrations have returned.

And now they threaten his place on the Rams’ 53-man roster.

With Cooper Kupp, Tavon Austin and Mike Thomas sidelined because of injury, the third preseason game against the Los Angeles Chargers lined up as a great opportunity for the Westlake High graduate to solidify his place on the Rams’ roster for a second straight year.

Instead, Spruce, who missed all of last season because of injury. was listed among the team’s inactive players and he missed the 21-19 loss at the Coliuseum.

Related: Ex-Westlake teammates Bercovici, Spruce reunite during preseason game

Rams head coach Sean McVay revealed earlier in the week that Spruce has been limited by injury throughout preseason, including the calf injury that ruined his rookie campaign.

“When Nelson’s been available, you can see he’s a conscientious football player,” McVay said on Wednesday. “(He) just has a good feel for the game, good natural hands.

“Unfortunately, he’s struggled with just some rare injuries, whether it be his calf or some pulls here and there. Not being able to be available has made it a little bit difficult."

McVay compared Spruce’s situation with Austin, who has missed nearly all of training camp with a hamstring injury.

“He’s done a good job of being attentive in the meetings, trying to rehab the best that he can,” McVay said. “Unfortunately, when you’re not healthy, it’s hard to compete at the best level that you want to. But I’ve been pleased with Nelson and what he’s done.”

Rams starting quarterback Jared Goff, who is close with Spruce, said the receiver has been itching to get back on the field and deliver the type of preseason performance the Rams saw from him last year against Dallas.

“Through the offseason, he’s just worked really hard, worked really hard to get himself ready and get himself back,” Goff said. “I think he’s been excited this preseason to get out there and to get to play again. Ultimately, that’s what he wants to do is make plays.”

Spruce had a team-high six catches in the Rams’ 13-10 win over Dallas on Aug. 12.

But he had a limited role in the 24-21 win at Oakland on Aug. 19, when he returned punts and only lined up offensively after Mike Thomas was injured late in the game.

Spruce, who has spent training camp listed third on the depth chart, was one of 22 Rams who did not participate Saturday night, including Kupp, running back Todd Gurley and most of the starting defense.

Spruce was unavailable after the game Saturday night, but Chargers quarterback Mike Bercovici, who was a teammate of Spruce’s at Westlake High, told The Star’s Bob Buttitta that Spruce was hoping to improve enough this week to play the Rams’ final preseason game in Green Bay.

When it was announced in July, Thomas’ four-game suspension for violating the NFL’s performance-enhancing drugs policy seemed to increase the likelihood that Spruce would return to the roster for a second season.

But the Rams added a top receiver earlier this month, when they traded for Sammy Watkins, and the position group, which is loaded with young, unproven but promising talent, remains one of the most difficult to predict on the team.

“Adding a player like Sammy, where you know he’s going to be a part of what you’re trying to do, it certainly does change a little bit,” McVay said last week. “But I think those guys, their mindset and their mentality is, ‘I’m going to go out every single day and play to the best of my ability.’

“With the uncertainty and the unpredictability with the injuries and different things that can occur, I think you get yourself caught up in worrying about things that you can’t control and that’s when it affects your ability to be your best. Those guys aren’t players that do that and I think that’s why you appreciate what they bring to this team right now.”