BOSTON – The Boston Red Sox are moving Daniel Bard to the bullpen — temporarily, at least.

With rain washing out Bard’s scheduled start against the New York Yankees on Sunday night, Manager Bobby Valentine said Bard will skip his turn in the rotation and be available in relief. But when the Red Sox need a fifth starter on Friday, it will be Bard.

“He’s pitched very well as a starter,” Valentine said.

A day after the Yankees overcame a nine-run deficit with back-to-back seven-run innings to beat Boston 15-9, the finale of their three-game series was postponed by rain. The Red Sox called the game about five hours before the scheduled 8:05 p.m. first pitch — no doubt because of rain that was falling all day and expected to continue through the night.

Bard has made two starts, one bad and one better, but he lost both and has a 4.63 ERA. Valentine said he would like to use Bard in the eighth inning early this week because he’s comfortable with the role.

Jon Lester will start tonight’s game against the Twins, and he’ll be followed in the rotation by Josh Beckett, Clay Buchholz and Felix Doubront. Bard’s next turn would be Friday.

The Yankees pounded the Boston bullpen Saturday for seven runs in the seventh inning and seven more in the eighth, their biggest rally after a nine-run deficit since April 18, 1950, when they trailed the Red Sox 9-0 after five innings and went on to win 15-10.

The Detroit Tigers rallied from an 11-1 deficit to beat the Washington Senators 18-12 on June 12, 1938.

“To come back in the (sixth) inning being down 9-nothing to the Red Sox, to be able to get the win, that’s a big win for us,” said Nick Swisher, who hit a grand slam and had six RBI. “That’s all I can really say. I really don’t know what else to say.”

Because Sunday night’s game was scheduled to be on ESPN, Terry Francona was supposed to be in the booth to analyze his former team. The rainout saved the Red Sox from that awkward situation.

It also delayed the Boston debut of newly acquired outfielder Marlon Byrd, who was traded to the Red Sox from the Chicago Cubs on Saturday night. Byrd was scheduled to start in center field as Boston tries to fill in for injuries to Carl Crawford and Jacoby Ellsbury.

To make room for Byrd on the 40-man roster, the Red Sox designated Nate Spears for assignment.

Valentine tried to be optimistic about the fact that Byrd, a 2010 NL All-Star, has just three hits in 43 at-bats this season.

“He isn’t hitting right now; that’s the good news, which means he’s saved up all his hits for us, which is a good thing for him to do,” said Valentine.

The Red Sox also placed outfielder Jason Repko on the 15-day disabled list and said they would bring up Lars Anderson from Triple-A Pawtucket.

Anderson, normally a first baseman, has been used in the outfield this season in Pawtucket. Valentine said he would use Anderson in the outfield or as a left-handed pinch-hitter.