Can you imagine Jason Varitek wearing any other uniform? Can't do it, can you?

"That would be hard," Derek Jeter said.

How about you, Mariano Rivera?

"He's their captain," he said. "That tells you what he means to them."

Indeed.

"When you think of the Red Sox, he's one of the people that comes to mind," Joe Torre said.

Wait, there's more.

"It's the way he plays the game, the respect he has for the game," Josh Hamilton said.

For a decade, Varitek has represented the Red Sox with grace and grit. He might be the poster boy for some of the best years the franchise has ever had -- six playoff appearances, including two championships, in 10 seasons.

He has helped changed the way people perceive the Red Sox. Once lovable losers, they're now widely respected both for winning and for doing it the right way.

He's not the only Red Sox player who typifies this approach. Tim Wakefield, Mike Lowell, Mike Timlin and others provide a leadership core as solid as any in the game.

That "C" on Varitek's jersey speaks volumes. He's the Red Sox captain in every sense of the word.

Recently, when he briefly snapped out of a terrible slump with a hit, the Red Sox celebrated as if they'd won another championship.

"It's what he means to us," Red Sox manager Terry Francona said. "He got that hit in New York, and you see 24 guys and a manager and a couple of trainers rooting for him."

But nothing lasts forever.

Varitek's future with the Red Sox has become a hot topic on Boston sports radio at a time when he's hitting .218 and sometimes looking overmatched at the plate.

Because he is 36 years old, because he is unsigned after this season and because the Red Sox have had acquiring a catcher on their to-do list for more than a year, the previously unthinkable has become thinkable.

Money could become an issue. Varitek is represented by Scott Boras, and rumors have Boras seeking a four-year contract for Varitek.

Varitek's value could change depending on how the second half of the season goes, who the Red Sox acquire and how the season plays out.

To anyone Red Sox fan ready to throw Varitek off the bus: Be careful what you wish for.

When the Red Sox trailed the Cleveland Indians 3-1 in the American League Championship Series last fall, Varitek was one of the guys who set a relentless one-game-at-a-time tone in the clubhouse.

Had you walked into the Boston clubhouse before Game 5, you might have thought the Red Sox were preparing for a June game with the Mariners. That's because they play the game one way -- and Varitek is partly responsible for that.

There's no debating his offensive season. It has been terrible. Varitek's .218 batting average is 46 points below his career average. He's hitting just .184 on the road and .192 with runners in scoring position. He has put together back-to-back tough months -- a .122 average in June, a .188 average in July.

And yet at this point in his career, considering the makeup of this club, offense isn't his primary responsibility.

Even with Varitek not hitting, the Red Sox are second in the American League in runs, first in on-base percentage and third in home runs.

With J.D. Drew having a career year, with Dustin Pedroia becoming an impact player and with David Ortiz due back from the disabled list next weekend, Boston's concerns are mostly with middle relief and the back of the rotation.

As for Varitek, it might be impossible for an outsider to understand his impact in the clubhouse.

He keeps charts on every Red Sox pitcher and studies scouting reports and video before each game. He picks the brains of scouts, coaches and anyone he thinks can help with that day's game.

"Whether I'm hitting or not, I can influence other parts of the game," he said.

But what about the offensive struggles? He continues his workaholic ways, hoping to find a way out.

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What Varitek mainly does is set a tone for everyone else. When his peers voted him onto the American League All-Star team, he was asked over and over if he felt bad about going when he's hitting so little.

"No," he said. "That's a pretty good honor, to be sent by the players."

Sometimes Francona seems to know the questions are coming before they're asked.

"That is from the players around the league," he said. "That's how they feel about him."

As Pedroia told the Boston Globe, "He's all about us. He'll sacrifice himself for the team every time."