GLENDALE, Ariz. -- Two preseason games left and two chances to make that all-important impression. All with two cutdown dates looming.

Tonight's preseason game against the Arizona Cardinals may be just another August exhibition to Chargers veterans, but it's vital for those players craving one of the few open roster spots.

The Chargers must cut a dozen players by Tuesday and another 22 by Sept. 1. The decision process won't be an easy one for general manager A.J. Smith.

"I don't know if it's going to be any tougher (than past years) because I have to wait and see who the borderline guys are," Smith said. "I will say this -- I think, for the first time, that our football team is pretty much made. We pretty much know who our starters are and who our backups are."

A detailed scan of the Chargers' roster allows for an educated guess that perhaps just two spots on the 53-man roster are undetermined. That leaves a lot of players vying for those spots or perhaps setting their sights on cracking the team's eight-player practice squad.

Free-agent hopefuls like linebacker Nick Roach know the numbers and what's at stake but remain undeterred. Roach knows that tonight's game -- or Thursday's against San Francisco -- could decide his immediate future, but he refuses to get anxious over the situation.

"It's kind of like the draft -- you never know how it's going to shake out," said Roach, an undrafted free agent from Northwestern. "The best thing you can do is just make sure you're ready when the time comes to make a play.

"Just make plays. Do something to get noticed."

There will be fewer chances for young hopefuls to make an impression tonight since the starters -- except for running back LaDainian Tomlinson, who will sit out again -- will play into the third quarter before being removed.

Coach Norv Turner wants the starters to get the feel of a regular-season game and come out of the locker room at halftime to play another series or two.

"The number of opportunities will be limited for some of the guys you're talking about, but they will get playing time in the second half or the third quarter or the fourth quarter," Turner said. "I don't put a major emphasis on one play or one quarter. We've gotten to see these guys for a long time.

"There are things a guy can do to turn your eye. And certainly, there are things a guy can do to make you say, 'Oh, maybe he's not ready.' We've had a great look at these guys up to this point."

Smith said he considers more than just exhibition games when it comes to making roster cuts. He's aware that circumstances within a game could knock someone out of the rotation or limit playing time.

"You just evaluate it on everything -- minicamp followed by training camp followed by how much time does a guy get in a game," Smith said. "If they happen to get some activity and production, that's great.

"We have to rely on whatever information we have and make our determination. Whatever we've got to work with at the end is what we do."

One of the top training camp performances has come from running back/returner Darren Sproles, who missed all of last season because of a broken ankle. Sproles returned a punt 81 yards for a touchdown last Saturday against St. Louis and has been productive both running and catching the football.

But Smith can't yet say that Sproles has done enough to make the team.

"Darren is in the middle of everything," Smith said. "And he was in the middle of everything when we started and he's certainly in the middle of everything based on his performance. There's no question.

"He was drafted for a reason -- to be a return guy first. We know last year he got hurt, and that was a wasted year. I'll say this about him: He's back. He's back big-time and in the mix.

"I've been very, very pleased with him as a returner first and I think he's made a pretty good impression when he's been asked to do other things out of the backfield and running the ball."

Contact staff writer Mike Sullivan at (760) 739-6645 or msullivan@nctimes.com.