Angels demote struggling Joel Pineiro to bullpen

Struggling right-hander Joel Pineiro was pulled from the rotation and sent to the bullpen Thursday, but Manager Mike Scioscia won’t name a replacement until early next week.

With Monday’s off day and the anticipated suspension of ace Jered Weaver for throwing near the head of Detroit catcher Alex Avila last Sunday, the Angels won’t need a fifth starter until Wednesday night at New York.

Among the in-house candidates are relievers Hisanori Takahashi and Horacio Ramirez, who both have extensive starting experience; triple-A right-handers Trevor Bell, Jerome Williams and Eric Junge; and double-A right-hander Garrett Richards.

Richards, the organization’s top pitching prospect, took a 12-1 record and 3.04 earned-run average into Thursday night’s start, so he would be in line to pitch Wednesday on one extra day of rest.

“He’s in the conversation,” Scioscia said of Richards, 23, who was a compensation pick after the first round in 2009. “He’s a guy who has come a long way.”

Weaver appealed his six-game suspension and will pitch Friday night against Seattle. Tyler Chatwood will start Saturday and Ervin Santana on Sunday.

Weaver is expected to drop his appeal after Friday night and begin serving his suspension Saturday, which would put him in line to pitch Aug. 13 in Toronto.

Under that scenario, Dan Haren, who started Thursday night against the Minnesota Twins, the replacement starter and Chatwood would pitch Tuesday, Wednesday and Thursday, respectively, in New York, and Santana would start in Toronto on Aug. 12.

“We’re going to need a fifth starter somewhere next week,” Scioscia said. “There are a number of scenarios, and some of it will be contingent on where Weaver’s suspension falls.”

Pineiro was tagged for seven runs and seven hits, including two home runs, in 41/3 innings of Wednesday night’s 11-4 loss to Minnesota and is 0-3 with a 14.85 ERA in his last four starts.

The 32-year-old, who gave up 22 earned runs and 29 hits in 131/3 innings of the four games, will be relegated to a mop-up role, which will make it difficult to retain the form that made the sinker-ball specialist an effective starter for much of the last two seasons.

“He’ll take a step back and exhale, that’s for sure,” Scioscia said. “As far as getting functional work in a game, it will be hit or miss. The bottom line is, where J.P. is now, where he’s shown he can be and where we need him, that divide was widening, and we need him to take a step back and move forward.”

Abreu sits

Designated hitter Bobby Abreu, mired in one of the worst slumps of his career, was not in the lineup against Twins left-hander Francisco Liriano on Thursday night.

Abreu, 37, leads the Angels in on-base percentage (.373) and walks (67) but has only 12 hits in 81 at-bats in 23 games since July 4, a .148 clip that dropped his average from .289 to .258. After hitting 20 home runs in 2010, he has four homers and 42 runs batted in this season.

“He’s made some adjustments and his bat speed looks fine — he’s just not squaring the ball up,” Scioscia said. “One thing he’s still doing is working counts and taking walks.

“Though his average and production hasn’t reflected what we need, hopefully when he starts to square some balls up, he’ll be the package we’re looking for in the middle of the lineup.”

mike.digiovanna@latimes.com