BOSTON – Facing three games in a 24-hour period because of the expected arrival of Hurricane Irene, Boston added a 13th pitcher Friday, recalling right-hander Scott Atchison from Pawtucket and sending catcher Ryan Lavarnway to the Triple-A team.

Atchison, returning to the Red Sox for the fifth time this season, was 0-0 with a 4.70 ERA in nine relief appearances earlier this season.

“We just wanted to protect our bullpen,” Manager Terry Francona said prior to Friday night’s series opener with the Athletics — the teams are then scheduled to play a split double-header today, the second game pushed back from Sunday before the expected storm.

Lavarnway, recalled because of injuries to Kevin Youkilis and David Ortiz, was impressive in his seven-game major league debut, going 7 for 23 (.304) with three RBI, mostly as a designated hitter.

Lavarnway had a .407 on-base percentage, walking four times to go with six strikeouts.

Francona said Lavarnway, who hit 30 homers and drove in 85 runs combined for Double-A Portland and then Pawtucket, will be back with the Red Sox when the rosters expand next Thursday.

“He helped us win some games. That’s what we asked him to do and it’s not an easy thing to do,” Francona said.

“I think the experience is probably really good for him. He’ll be back. He’ll be back as soon as we can get him back here and spend September with us, hopefully learn some more.”