Scioscia is not overly worried about Shields

Scot Shields has a 3.54 earned-run average in 18 appearances, limiting opponents to nine hits in 66 at-bats in 20 1/3 innings, a statistical line most relievers would be glad to have.

So, why are so many wondering what’s wrong with the Angels right-hander?

Two reasons: Four of the hits Shields has given up were home runs, two of them game winners, including Cleveland slugger Travis Hafner’s three-run shot April 12 and Texas outfielder Nelson Cruz’s walk-off shot Sunday.

One of the homers tied the score in the eighth inning and led to a loss, and one was a grand slam that trimmed a five-run Angels lead to one. Shields had given up 19 home runs in the previous three seasons combined.

Second, the setup man has spoiled Angels fans for the last three years, posting a 25-20 record with a 3.00 ERA in 212 games, striking out 291 and walking 101 in 284 2/3 innings. He has been so reliable and dominant that most are shocked every time he gives up a run or loses a game.

“Right now, he’s had a little tough run, but anybody who pitches in the role Scotty does, everything’s going to be magnified,” Manager Mike Scioscia said. “There have been some games that have gotten away from him, but he’s been terrific most of the time. His ability to turn the page is what makes him very good in that role.”

Shields leads the Angels in appearances -- nothing new there; no big league reliever threw more innings than he did from 2004 to 2006 -- but said fatigue has nothing to do with his occasional struggles.

“I feel real good physically,” Shields said. “My pitches are moving well. My velocity is fine, in the 93-94-mph range.”

But one other statistic jumps out besides the home runs -- Shields has walked 10 and hit one batter; he averaged 34 walks and two hit batters over the previous three seasons.

“One of the things with Scot is, his delivery adds deception, but it’s not real clean,” Scioscia said. “At times he’s out of sync, and he might struggle with his command ... and occasionally walk a guy. But I don’t think it’s anything out of the ordinary what he’s doing.”

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Scioscia spoke Sunday evening with Bob Watson, and baseball’s vice president in charge of discipline, rules and on-field operations is reviewing umpire Alfonso Marquez’s decision to eject Hector Carrasco after the Angels reliever hit Ian Kinsler in the helmet with a 78-mph breaking ball in the seventh inning Sunday.

Scioscia fumed that Carrasco was tossed, while no action was taken against Texas reliever Joaquin Benoit, who hit Gary Matthews Jr., who had homered twice, with a 94-mph fastball in the top of the seventh.

Crew chief Rick Reed said it didn’t matter that Kinsler was hit with an off-speed pitch; what mattered was he was hit in the head, leaving Marquez little choice but to eject Carrasco.

“I think it will be reviewed, and we’ll get an interpretation,” Scioscia said. “Obviously, in the small picture it doesn’t mean much, but it’s nice to get some guidelines as we move forward.”

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Second baseman Howie Kendrick (broken bone in left hand) will begin a minor league rehabilitation assignment with triple-A Salt Lake tonight.

mike.digiovanna@latimes.com