Mike Timlin, the veteran reliever, could also see time finishing out games.

The Providence Journal / Bob Breidenbach

FORT MYERS, Fla. — The Boston Red Sox open their exhibition season tonight against the Minnesota Twins.

As they enter this part of spring training, the Red Sox really have only one major question mark in preparation for the 2007 season, which begins in Kansas City on April 2.

That question comes from the bullpen, where Boston has to find a closer.

The auditions for the role begin tonight at City of Palms Park. Pitching coach John Farrell has designated Joel Pineiro, Brendan Donnelly, Julian Tavarez and Mike Timlin as the candidates for the job, and each of those right-handers, with the exception of Timlin, will get an inning of work tonight. Timlin experienced back spasms on Sunday and will be held out as a precautionary measure.

But while Farrell watches those veterans to determine who should be entrusted with the crucial ninth inning, he already has a lights-out closer on the roster.

He’s Jonathan Papelbon.

Papelbon has had success as a closer, earning an All-Star berth last year. And best of all, the right-hander revels in the role, relishing the challenges inherent in the job.

But, as has been well documented, the Sox want Papelbon in the starting rotation, at least to begin the year, to protect his right shoulder, which popped out on him last Sept. 1.

While Papelbon is a willing starter — “Boston drafted me as a starting pitcher, so this is the way we want to go now” — it’s not the same as closing, he admits.

“I’ll miss the fans wanting me to come in. I’ll miss that feel, when the game’s on the line. It’s a totally different feeling than starting. It’s night and day. I’ll miss closing. It was a joy for me,” said Papelbon, who finished the year with 35 saves in 41 chances, along with a 4-2 record and a 0.92 earned-run average.

Sending Papelbon back to the rotation isn’t an easy decision for the Red Sox, especially given their options for his replacement. But the Boston brass figures Papelbon can be equally successful as a starter.

“We’d rather have a shut-down closer than a fourth starter and we’d rather have a top-of-the-rotation starter than a middle-of-the-road closer,” said general manager Theo Epstein recently.

“He could be every bit as valuable as a starter as he was last year, though it’s hard to be more valuable than he was last year. If he falters in the rotation, it might be different [meaning a shift back to the bullpen, provided his shoulder is healthy], but I don’t think that will be the case,” said Epstein.

Only a year ago, at least for the first half of the season, Papelbon was the best closer in the majors. He successfully wrapped up saves in his first 20 opportunities. His earned-run average was a miniscule 0.24 on June 24, when he was 2-1 with 23 saves in 24 chances.

It wasn’t just that he was saving games. It was the manner in which he was closing them out, his sizzling arsenal of pitches giving the opposition no chance.

But, in his youthful exuberance, his right shoulder began tiring to the point where he suffered a subluxation of the joint, his shoulder popping out on Sept. 1 against Toronto, forcing him to leave the mound.

Surgery wasn’t required, but the Sox have decided that he is better off in the starting rotation, pitching on designated days with four days in between to continue his strengthening program. That, reasons the medical staff, is better for his long-term health than pitching stressful innings on back-to-back days, or maybe even four times a week.

So while Papelbon still may shift to the bullpen later in the season, he is expected to begin the year in the rotation. And that’s fine with him.

“If you asked me halfway through last season I would have said that I wanted to close for the next 10 years. Everything was going great,” said Papelbon, 26, a 6-foot-4, 230-pounder.

“But this is a decision we made as a staff and as a person and we’re going to go with it,” he said.

Papelbon’s late-season injury gave him pause to reflect on his career.

“I’ve taken this for granted. I can’t really do that. Maybe that’s why I got hurt. You don’t know. Things happen for a reason,” said Papelbon, who was 0-0 with a 2.25 ERA in three starts for Boston in 2005 before being shifted to the bullpen.

“This [pitching] is my livelihood, what I know, what I do, what gets my motor running. The mound is my safe haven. That’s where I feel comfortable. And if I can’t do it again? That really hit home,” he said.

So Papelbon has been diligent about doing his conditioning work. He’s been working on regaining the feel for his curveball, a pitch he didn’t need as a closer. And while he says he feels no pressure in the rotation, Papelbon says he wants to be considered a guy his teammates can count on in the rotation, as they counted on him coming out of the bullpen.

But the best part of training camp so far for Papelbon, who will make his spring debut on Saturday, following Tim Wakefield to the mound against the Phillies, is that his shoulder is healthy.

“I’m pain-free,” said Papelbon. “As long as I keep up with my shoulder program, I’ll be cool.”

He paused for a moment.

“It’s all good,” he added.

The Red Sox only hope they can say the same thing about their closer come the end of camp, whoever he may be.

skrasner@projo.com