Minneapolis, MN (AP)  -- The Boston Red Sox designated reliever Julian Tavarez for assignment Monday, clearing room for the return of first baseman Sean Casey.

Tavarez, who turns 35 later this month, was 0-1 with a 6.39 ERA in nine games. The right-hander allowed 18 hits and nine walks in 12 2-3 innings.

The Red Sox have 10 days to trade, release or send Tavarez to the minors. He made his major league debut in 1993, has played for eight teams and first joined the Red Sox in 2006.

Tavarez filled a hole in the rotation last season, making 23 starts. He was more of a "safety valve" for the staff this year, manager Terry Francona said.

"He was always there for insurance. Not the most glamorous job, but he'd take the ball back-to-back," Francona said, adding: "We thought we can win more with the other pitchers."

Francona acknowledged the move was a sign of confidence in right-hander Craig Hansen, the team's first-round draft pick in 2005.

Casey was activated from the 15-day disabled list after recovering from a strained right hip. He hurt himself running the bases April 25 and spent a two-game rehabilitation assignment with Triple-A Pawtucket.

Batting .346 with six doubles and eight RBIs in 52 at-bats, plus a .424 on-base percentage, Casey started at first base Monday at Minnesota in place of streaking Kevin Youkilis. Francona said he wants to give all his regulars one day off this week.

In other developments, left fielder Manny Ramirez was back in the lineup after resting a sore right hamstring Sunday. He pinch-hit in that loss.

Coco Crisp was in center, with Jacoby Ellsbury -- still smarting a bit from being hit by a pitch on the inside of his left knee the night before -- on the bench.

"Just keep revolving them," Francona said of his outfielders, Ramirez, Crisp, Ellsbury and J.D. Drew.

Shortstop Julio Lugo was still out while recovering from a mild concussion. He rode a stationary bike before the game, and his status was considered day to day.