BOSTON -- Ralph Treuel took over as Red Sox pitching coach Monday, a move of curious timing.

"It was my decision to make," Boston manager Joe Kerrigan said. "This being an off-day today, I thought it was the right time to bring Ralph in."

The promotion of Boston's minor league pitching coordinator followed the third straight strong performance by a Red Sox starter.

After eight scoreless innings Sunday night, David Cone gave up an unearned run in the ninth and the New York Yankees won 1-0 behind Mike Mussina, who lost his bid for a perfect game with two outs in the ninth.

"Aside from the end result, watching a game like that is an awful lot of fun," Kerrigan said.

There wasn't much fun in the Boston clubhouse after the game as players, including Nomar Garciaparra, complained about the departure of John Cumberland, Boston's bullpen coach for the third straight year.

But Kerrigan said he didn't detect any complaints while talking to players.

Cumberland moved into the dugout to help Kerrigan with the pitchers, but the Red Sox were careful not to call him the pitching coach. The club said he was reassigned to their minor-league base in Fort Myers, Fla.

"He said that he was going home for a while," Kerrigan said.

The move came after an outstanding series by Boston's starters. Frank Castillo, Pedro Martinez and Cone allowed 10 hits and no earned runs in 21 1-3 innings, but Boston lost all three games.

The off-day gave Kerrigan, who had been pitching coach until he succeeded the fired Jimy Williams on Aug. 16, a chance to meet with Treuel and review hitters the Red Sox will face against Cleveland on Tuesday night.

He said he wanted to give Treuel a month to get comfortable with the major league surroundings rather than delay the move until the end of the season. But Kerrigan wouldn't say if Treuel will be back next year.

"We will leave, basically, our options open," he said, adding: "We have a very close working relationship."

The Red Sox are for sale and there's a chance new owners could be in place before next season.

Treuel, who pitched in the Detroit system from 1974-82, was pitching coach for Detroit in 1995 and in the Red Sox system for three years before becoming minor league pitching coordinator in 1999.

He said he first met Boston general manager Dan Duquette in the spring of 1996 "and we've had a very good working relationship."

Kerrigan wouldn't elaborate on whether "performance issues" cited by the club in replacing Cumberland extended beyond baseball.

"Any issues regarding things off the field or outside baseball issues are held in the strictest confidence by the organization," he said.

Kerrigan said he didn't promote Treuel when he became manager because minor league field coordinator Dave Jauss already had been added to the Boston coaching staff and he didn't want to take the pitching coordinator at the same time.