As preseason comes to an end, there are still a few fighting for a spot on the Chargers’ roster

After it was finally over, all the practices and meetings and preseason games, he survived. Mercifully. Thankfully.

For an entire 24 hours.

Only then was Craig Mager cut.

As unforgiving as the NFL can be, one of the league’s cruelest weekends is about to arrive.

It is pure coincidence that as America recognizes Labor Day, hundreds of NFL wannabes lose their jobs.

A year ago, the Chargers cornerback initially was part of the team’s 53-man roster. He was waived a day later when Jeff Richards signed after being cut by Carolina.

The various moving parts resulted in Mager, who had appeared in 11 games for the Chargers in 2016, on the practice squad.

“Maybe the first two, three, four weeks I had a salty attitude,” he recalled this week. “I was feeling like I should be out there, that I could be making plays. Once I got over that, I settled in and starting being more positive about it.”

Mager, 26, spent all but two games last season on that practice squad. He finished the year with zero tackles, one fewer than quarterback Philip Rivers.

As the Chargers enter another preseason finale, at San Francisco on Thursday, Mager understands the reality of being on the roster bubble and the hard feelings that can come with failure.

“You being bitter is just you focusing on other people,” he said. “If you’re sitting there having a bad attitude, it’s because you think you’re better than this guy or that guy. But you didn’t go out there and show it.”

A lot of Chargers hopefuls are now facing their final chance to prove something, their last shot at a roster spot or a place on the practice squad.

The most obvious questions still unanswered concern Rivers’ backup, where Geno Smith appears to have the edge over Cardale Jones, and kickers, where Caleb Sturgis and Roberto Aguayo remain in competition.

Lingering minor injuries and the emergence of defensive rookies Derwin James and Kyzir White have left a few starting assignments for the season opener unresolved.

Otherwise, this final preseason game is about those precious slots at the back of the roster and the young players trying to show they belong.

“We’ve been reminding them of that all week,” coach Anthony Lynn said. “Just telling them some inspirational stories.”

One of those stories was about Austin Ekeler, who made the Chargers’ 2017 roster largely on the strength of the preseason finale, when he totaled 108 yards on eight rushes and three receptions.

Detrez Newsome, an undrafted rookie running back, is in a similar position this year. He has more carries (35) and catches (nine) than any Charger in the preseason. Yet, he has secured nothing to this point.

While the coaches have been complimentary of Newsome over the past several days, they also have been careful to note that the battle for running back depth isn’t over.

“I’m more anxious than anything,” Newsome said. “It’s the last game, so I have to give it my all and control what I can control. It is definitely a scary spot to be in.”

Having positioned himself well to make the team, Newsome now will face more competition in fellow rookie Justin Jackson.

A seventh-round pick out of Northwestern, Jackson is set to make his first preseason appearance Thursday after being out with a hamstring injury.

“We had some guys who did good in spurts,” offensive coordinator Ken Whisenhunt said, referring to the third preseason game. “But … it was hard to single out anyone. That’s what this week is for. This is a big week for some of those guys to show where they really are.”

And to show where they really deserve to be after this weekend, which is on the Chargers or out of a job … or maybe on the practice squad, which isn’t as salty a place as it might appear to be at first.

“It’s so easy to be watching football at home and go, ‘Man, that should be me,’ ” Mager said. “If you look at it that way, it can definitely be detrimental. The idea is to look at it as an opportunity, an opportunity to get better.”

jeff.miller@latimes.com