The Red Sox had apparently made the decision even before Saturday night's latest bullpen disaster: Byung-Hyun Kim is heading to the 'pen to assume the closer's role.

Kim, a full-time closer before this season in the starting rotation, could be moved to the bullpen as early as Sunday against the Florida Marlins, the Boston Globe reported.

Kim was traded by the Arizona Diamondbacks to the Red Sox for third baseman Shea Hillenbrand on May 29. As a starter for Arizona and Boston, Kim is a combined 3-6 with a 3.38 ERA in 12 starts. Kim made the All-Star team as a closer last season; he finished with 36 saves and a 2.04 ERA.

The Red Sox, trying to stay in contention in the AL East, have struggled mightily in the bullpen this season. Boston blew a 9-2 lead Saturday, giving up eight runs in the last two innings. Brandon Lyon, who moved into the closer's role last month when the likes of Alan Embree and Chad Fox failed, gave up four runs in the ninth, including Mike Lowell's two-out, three-run homer in the 10-9 loss to Florida.

There have been reports that the Red Sox were interested in trading for a closer, possibly Armando Benitez of the Mets. It appears the Red Sox have settled on Kim as their closer, for now.

Ramiro Mendoza, who has spent most of his career as a reliever, may eventually take Kim's spot in the starting rotation. Mendoza is expected to rejoin the team Tuesday as the Red Sox open a series with the Devil Rays. Mendoza is on the disabled list with tendinitis in his right knee.

"All our reports have been good on [Mendoza] the last week," manager Grady Little told the Globe. "We'll watch him throw on the side [Tuesday] and go from there."

According to the Globe, the Red Sox are eager to restructure their pitching staff in time for their series in New York against the first-place Yankees beginning the afternoon of July 4.