SAN FRANCISCO (AP) — Giants left-hander Noah Lowry will undergo arthroscopic surgery Tuesday on the back of his elbow to remove bone spurs, another setback for someone expected to be a key member of San Francisco’s rotation this year.

The 27-year-old Lowry has spent the entire season rehabilitating from a March 7 operation to repair a rare nerve problem in his forearm called exertional compartment syndrome.

Lowry had been on a throwing program in Arizona and was close to pitching in the Arizona instructional league. He also had been scheduled to pitch in winter ball, though that is now doubtful.

The recovery time for Lowry’s surgery, which will be performed by Dr. Lewis Yocum, is expected to take about six weeks.

Cubs’ Soto leaves game during at-bat in sixth

MILWAUKEE — All-Star catcher Geovany Soto left the Chicago Cubs’ game against the Milwaukee Brewers in the sixth inning Friday, grimacing and shaking his left hand after fouling off a pitch.

Manager Lou Piniella and a member of the team’s training staff talked to Soto briefly at home plate before replacing him with Koyie Hill.

Soto was scratched during a game earlier this month because of soreness in the hand.

Santana is ready to pitch on short notice

NEW YORK — Johan Santana is ready to pitch on short rest today if the New York Mets need him.

Still fighting for a playoff spot, the Mets were undecided on a starter for today against Florida. Injured right-hander John Maine has been sidelined since August, leaving a hole in the rotation, so New York has turned to rookie Jon Niese and journeyman Brandon Knight for crucial starts in September.

Santana, slated to pitch the season finale Sunday, threw a career-high 125 pitches Tuesday in a win over the Chicago Cubs. He told manager Jerry Manuel on Thursday that he could come back to start today if the team thought it was best.

Yankees’ Rivera may have offseason surgery

BOSTON — New York Yankees closer Mariano Rivera is considering whether to have offseason surgery on his sore right shoulder.

General manager Brian Cashman said before Friday night’s scheduled game against the Boston Red Sox that Rivera can pitch through the pain until the season’s over. But over the winter, Rivera will need treatment or surgery for calcification of the A.C. joint on the top of his shoulder.

Also Friday, Girardi said that starter Andy Pettitte was on his way to the ballpark after leaving the team to have a second MRI on his right shoulder. The results were encouraging, the manager said.

Williams say contract extension no priority

CHICAGO — White Sox general manager Ken Williams said Friday his own contract extension was the lowest of his priorities while Chicago tries to make the AL playoffs.

“Whatever is last on the list, that’s under it,” Williams said while sitting in the dugout before the opener of a three-game series against the Cleveland Indians. The White Sox began the night one-half game out in the AL Central.

Milwaukee to pitch Sheets today

MILWAUKEE — Brewers pitcher Ben Sheets looked interim manager Dale Sveum square in the eyes and told him he thought he’d be ready to go today.

That’s all Sveum needed to hear.

Sheets will start today against the Cubs despite a sore elbow that forced him to leave his last appearance on Sept. 17 against Chicago.