01:00 AM EST on Friday, March 24, 2006

FORT MYERS, Fla. -- Most of the Red Sox have been here for well over a month now, and there is only a week left to their Florida stay. They've played 21 Grapefruit League games -- won some and lost some. Their Opening Day roster is practically set.

Still, the Red Sox know very little about their 2006 prospects. In some ways, it's as if they've been running in place since the middle of February.

Beginning this afternoon, that could change. By Monday or so, they'll know a whole lot more about themselves, because by then they'll know a whole lot more about Keith Foulke.

Over the winter, the Red Sox re-made their entire infield, obtained a new leadoff hitter and center fielder, added a new backup catcher, a No. 2 starter and no fewer than three new veteran relievers.

But none of it will mean much if Keith Foulke can't pitch a whole lot better than he did last season. If the Sox don't have an effective, proven and reliable closer, then they won't have much of anything.

When Foulke was first ineffective, then injured last year, it forced the Red Sox to re-arrange their pitching staff. First, they used Curt Schilling, then they tried Mike Timlin. In between, they very nearly gave the job to Craig Hansen, who had been pitching in college when Foulke's season began to implode.

During the offseason, they were concerned enough about Foulke's ability to rebound that they were on the periphery of the free-agent pursuit of Billy Wagner. After failing to land an established closer, the Sox set out to bolster their setup personnel.

But as critical as Julian Tavarez, David Riske and Rudy Seanez will be to their success or failure, much of the burden will fall to Foulke. If he's as good as he was in 2004, the Red Sox can be as good as any team in the game. If he falters, they could be in big trouble.

There aren't a lot of in-house options if Foulke fails. Surely, the Red Sox don't want the 40-year-old Timlin sliding into a role he's never relished. As for Tavarez, Riske and Seanez, none has ever closed successfully.

Hansen, with exactly 13 career innings above Class A, isn't ready to handle the responsibility full time. That leaves Jonathan Papelbon as the only alternative. Papelbon has the stuff and, just as importantly, the makeup to handle the job. But shifting him into the closer's role would derail his progress and be a short-term fix.

Trades? Nobody is going to take pity on the Red Sox and deal them a proven closer in April.

So it falls to Foulke, and it begins today with an inning against the Ottawa Lynx.

The Red Sox have been careful to downplay expectations on Foulke, repeating over and over again that, so long as he's physically able, the closer's job is his.

"Foulke deserves my confidence," said manager Terry Francona yesterday, "because he's done it, and done it as well as anybody in baseball."

True enough. Even with his disappointing season of a year ago, only seven closers in baseball have accumulated more saves than Foulke since the start of the 2000 season. Among active closers, he's converted almost 85 percent of his save opportunities, and until last year had posted an E.R.A. of 2.97 or better for six straight seasons.

There are questions about his knees as he continues to receive injections of Synvisc in his surgically repaired knees. Moreover, there are questions about his head. Last year, beset by personal issues and his confidence beaten by poor mound performance, Foulke lashed out at fans and reporters. His body language often told it all.

This spring, he appears far more sure of himself, far more at peace.

"I think he feels pretty good about himself," said Francona.

As the manager acknowledged, today won't tell the Red Sox everything they need to know about Foulke. The hitters (Triple A) and conditions (a spring training stadium that will be half-full, at best) will merely attempt to replicate an actual big-league environment.

But Red Sox personnel will be watching to see how the ball comes out of Foulke's hand, how he commands his fastball, and whether he gets the proper separation between his fastball and changeup.

If all goes well, he'll try an inning tomorrow against the visiting Toronto Blue Jays, then will pitch again two days later against the Tampa Bay Devil Rays.

Cross your fingers, Red Sox fans. By Monday, the Red Sox will have a far better idea about Keith Foulke, and by extension, themselves.

smcadam@projo.com / (401) 277-7340