SAN DIEGO -- Shawne Merriman is the poker player who agonizes over whether he should call or fold.

He frets. He fusses. He slouches. He stares. He shuffles his chips. He checks his cards. He re-checks them. He repeats the routine again and again and again.

Then he folds -- every time.

Merriman, the Chargers linebacker and flamboyant sackmaster, says he wants to play this season. The Chargers say they expect him to play this season. You believe him. You believe them.

But you know how this soap opera is going to end. Merriman has two torn ligaments in his knee. He has a contract that expires after next season, when millions will be piled on the table.

As much as he wants to play, Merriman won't risk a career-ending injury. Not right now. He can't. There's no money in it.

Merriman reportedly was on a plane Monday headed for Miami, seeking yet another opinion on that gimpy knee, stalling the surgery that's sure to come.

Meanwhile, Jyles Tucker was lined up at the end of the Chargers' defensive line -- sometimes on the left side, sometimes on the right. Most every time he was making a mad dash toward Seattle Seahawks quarterback Charlie Frye during Monday's preseason game at Qualcomm Stadium.

Tucker, who earlier in the day signed a five-year contract extension, is a case study as to why the Chargers will be fine without Merriman and, at the same time, a painful reminder of why preseason injuries can be so devastating.

Tucker, the 6-foot-3, 258-pound undrafted free agent who spent most of last season on the Chargers' practice squad, has about as difficult an assignment as there is in the NFL this side of Green Bay and Aaron Rodgers. Merriman, after all, is the linebacker with the "Lights Out" nickname and more quarterback sacks (39 1/2) in his three seasons than any NFL player during the same span.

It was a scary night for Tucker. In the first quarter, he pushed and shoved and wrestled with an array of Seahawks linemen -- often conceding more than 100 pounds per tussle -- to little effect.

In the second quarter, Tucker ripped past a would-be blocker and had his arms wrapped around Frye's legs, only to have the quarterback wriggle free.

"I had his ankle, but I need to get that upper body so he can't get away from me," Tucker said. "Those are plays that need to be made."

In the third quarter, Seahawks center Ben Claxton was called for a 15-yard clipping penalty. Turns out Tucker was a casualty of Claxton's aggression.

"I don't know where the clip came from or what number it was, but I know it was a clip on somebody," Tucker said. "I'm just glad I could get up and walk away."

Tucker hobbled off the field and plopped onto a sideline trainer's table, where he spent most of the rest of the game with a massive ice pack strapped to his right ankle.

"It's fine," Tucker said. "I could have gone back in there and played. It's just a little bruise. I'm good."

Two seasons ago, the Chargers won all four games Merriman sat out while serving a league-mandated steroid suspension. There's no doubt they can win without him again.

"That's just the way the NFL is," Chargers linebacker Shaun Phillips said. "Somebody goes down, somebody else has to step up."

Problem is, there's a cap on how many players a team can lose and not implode.

The number depends on the team and the players. Thanks to guys like Tucker -- who had three sacks, two fumble recoveries and a touchdown in a one game last season -- the Chargers' haven't reached their melting point.

Tucker is the sort of kid -- humble, sincere, appreciative -- you want to see succeed. Other than the many, themed nicknames ("Mini Light," "Nite Lite," "Candlelight") bestowed on Tucker by his teammates, he has little in common with the man he was subbing for in the Chargers' 18-17 victory.

"I'm in a little bigger role than I had last year," Tucker said last week, even before specifics of Merriman's knee problems -- and Tucker's own ankle woes -- surfaced. "So I'm definitely trying to stay on my Ps and Qs. Get better, stay consistent and try to get to the top. That's the main key."

Listen to this kid. Ps and Qs? You gotta love him.

And when Jyles Tucker says he wants to get to the top, he isn't talking about Jyles Tucker. He is talking about the Chargers.

"Winning a championship, that's what it is all about," he said.

You believe him, too.

Contact sports editor Loren Nelson at (760) 740-3551 or lnelson@nctimes.com.