CLEARWATER, Fla. — Ordinarily, managers are the ones losing sleep over bullpen issues.

This spring, it was one of the pitchers.

Jonathan Papelbon, shifted out of the closer’s position last fall after concerns about his right shoulder, couldn’t sleep this spring. These weren’t nightmares about blown saves. These were restless nights about missed opportunities.

Simply put, he missed being the Red Sox’ go-to guy in the late innings.

Earlier this week, he spoke up about it — first with team captain Jason Varitek, then manager Terry Francona and finally general manager Theo Epstein. By yesterday morning, the starter experiment was over and Papelbon was again the team’s bullpen savior.

Jonathan Papelbon, pitching March 3 in Fort Myers, Fla., says he chose to abandon the starter experiment.

The switch came the same week in which Mike Timlin, his designated replacement as closer, discovered he would be placed on the disabled list at the start of the season. But both Papelbon and the Sox insisted the flip-flop had nothing to do with Timlin’s unavailability or the bullpen makeup.

“This was a decision I made,” said Papelbon, who saved 35 games in five months as a rookie before being shut down in September with shoulder issues. “This had nothing to do with Timlin [not] being healthy or us not having [an established] closer…Obviously, I’ve been thinking about it all spring. When I got to spring training, I wasn’t sleeping well. There was always the feeling that I wanted to close.”

(Ironically, Papelbon blew a one-run lead yesterday in the seventh inning, his first of three innings of work, in a 4-4 10-inning tie with Philadelphia).

Papelbon approached Francona on the field Tuesday night before the Sox’ game with the Minnesota Twins and relayed his wishes. That set in motion two mornings’ worth of meetings, which Francona yesterday labeled “extensive, intense and passionate.”

The Sox emphasized that Papelbon’s shoulder, which slipped out of its socket last Aug. 31, was far stronger than last fall, thanks to an intensive strength and conditioning program he undertook in the offseason.

“The most significant news about Pap was that he reported to spring training with a completely rehabilitated and reconditioned shoulder,” said Epstein, “one of the two of three strongest [in the organization]. [Last fall] the only move in our opinion was to put him in the rotation. But Pap has a great offseason. At that point, it became pretty clear, with the improvement, the degree of management would no longer require a stay in the rotation.”

Even after Papelbon answered questions about his shoulder’s stability, according to Epstein, the Sox preferred keeping him in the rotation. But when Papelbon began to express a longing for his former role, things evolved quickly.

“A player is not going to succeed in the starting role if he feels he’s a closer,” said Epstein. “He thinks of himself as a closer. He’s committed to doing this and doing it extremely well for the next decade. It was hard to argue with that. It became the right thing to do.”

Francona, who acknowledged yesterday that he often argues that a quality starter is more valuable than a quality closer, changed his stance.

“Not in this situation,” Francona said. “He’s unique. He’s at the top of the list of all the relievers in baseball. He impacts a ball club a lot.”

Papelbon, speaking hypothetically, told the Boston Herald that if he returned to close “there will be no four days in a row, no five days in a row. I have to have a better understanding with Tito when I’m going to come in and pitch. I’m not going to come in and pitch the eighth and ninth.”

But yesterday, while avoiding specifics, Francona said the Sox wouldn’t put pre-set limits to his usage.

“We’ll use common sense and good judgment,” said Francona.

Last year, of his 59 appearances, 18 — or almost one-third — were for more than an inning.

Papelbon will continue to remain on a strict program to maintain shoulder strength under the tutelage of assistant trainer Mike Reinhold.

“If I stay on the program,” said Papelbon, “there’s no reason I can’t pitch into October.”

Papelbon, who conferred with his wife, parents and agent before committing to the switch, indicated yesterday that his return to the bullpen is permanent.

“I’m not in this to pitch a couple of innings and leave,” he said. “I’m in for the long haul. This is something I’d like to do for the rest of my career and kind of forget about starting and go out there and chase records…and what Mariano [Rivera] has done with the Yankees, do for the Red Sox.

Indeed, for the first five months of last season, while compiling a 0.92 ERA and averaging more than a strikeout per inning, the Sox finally had a weapon to match Rivera. Papelbon could be used in tie games, in extra innings and for multiinning appearances.

But overuse — according to Francona, Papelbon threw more pitches in August than any other reliever in the game — caught up with him. Now, cognizant of his limits, Papelbon returns to the closer’s spot.

“Basically,” concluded Papelbon of his new-old assignment, “it’s where my heart is.”

And now he — and his manager — can presumably sleep far more soundly.

smcadam@projo.com