Boston (21-13) at Los Angeles (17-15)

The Los Angeles Angels’ rotation is about to get a big boost.

Ervin Santana(notes) will make his season debut Thursday when the Angels conclude a three-game series with the Boston Red Sox.

Injuries to Santana (sprained elbow) and John Lackey(notes) (forearm strain) plus the death of rookie Nick Adenhart(notes) jumbled the Angels’ rotation early this season. Including Adenhart, eight pitchers have started for Los Angeles (17-15), which begins play 1 1/2 games behind AL West-leading Texas.

The return of Santana (16-7, 3.49 ERA) could help begin to reduce that deficit. The right-hander was an All-Star in 2008, and also was fourth in the AL in innings pitched (219.0) and second in strikeouts (214). He made two rehab starts with Triple-A Salt Lake, but was kept to a pitch count of around 80.

“I feel good,” Santana told the Angels’ official Web site. “I’m ready to go, see what happens.”

Santana is 1-2 with a 5.83 ERA in five starts and one relief appearance against the Red Sox (21-13). He pitched in Game 2 of last season’s AL division series, allowing five runs over 5 1-3 innings, but didn’t factor in the 7-5 loss.

Lackey, who won 12 games last year, is scheduled to start Saturday against the Rangers in Arlington. Manager Mike Scioscia said both would be monitored.

“They’re going to have enough pitches to get deep in a game,” Scioscia said. “But they’re certainly not going to be in the 110- to 115-pitch range this early. I’d think they’d be between 90 and 100.”

The Angels are looking to win their fifth straight regular season series against the Red Sox, who knocked them out of the first round of the playoffs in 2004, 2007 and 2008. After losing the opener of this series, Los Angeles got another fine outing from an unheralded pitcher in an 8-4 win Wednesday.

Matt Palmer(notes) tossed a five-hitter for his first career complete game. The Angels have won eight of 10 with their starters going 7-1 with a 2.80 ERA.

“It’s amazing. The story writes itself,” said Palmer, now 4-0 with a 3.38 ERA. “But I don’t have a chance to pinch myself. I don’t have a chance to sit here and relax. I’ve got to pitch hard every game. If I don’t, then I’m out. That’s just the way it is.”

The Red Sox hope the return of reigning AL MVP Dustin Pedroia(notes) can help spark an offense which is 1 for 9 with runners in scoring position in the series.

Pedroia, who’s been out of the lineup since straining his right groin on Sunday, is hitting .320 in 32 games this season. He’s tied with Jacoby Ellsbury(notes) for the team lead with 41 hits.

“He looks good,” manager Terry Francona told the Red Sox’s official Web site. “He took extra (batting practice). He actually looks really good.”

Brad Penny(notes) (3-1, 6.90), who is coming off his longest start of the season, gets the start for the Red Sox. The right-hander pitched 6 1-3 innings against Tampa Bay on Friday, allowing three runs and eight hits in a 7-3 victory.

Penny is 2-3 with a 4.91 ERA in six starts against the Angels. On April 11, he allowed three runs and five hits over six innings of a 5-4 win.