LOS ANGELES - Dodgers right-hander Darren Dreifort is expected to have surgery on his right knee in the next couple of weeks and miss the rest of the season, the team announced Friday night.
Dreifort, 31, was examined by Dr. Ralph Gambardella, who diagnosed the pitcher's condition as a weak medial collateral ligament. The surgery, scheduled to take place June 17 or 18, requires a six-month recovery period. The operation will be performed by Gambardella and Frank Jobe.
Dreifort had Tommy John surgery on his right elbow in July 2001 and didn't pitch again until this season. It appeared he was going to return last summer, but he injured his knee during his rehabilitation and had to have arthroscopic surgery.
GUERRERO TO DL: Montreal slugger Vladimir Guerrero was placed on the 15-day disabled list with a herniated disc in his back.
The Expos will purchase the contract of infielder/catcher Edwards Guzman from Triple-A Edmonton today to take Guerrero's place. Guzman was batting .352 with three homers and 27 RBIs for the Trappers.
Guerrero will seek a second opinion next week to confirm the diagnosis and to determine how long he'll be out.
YANKS ADD FADING SLUGGER: New York acquired Ruben Sierra in a trade with Texas, a player who once called manager Joe Torre "a liar."
The Yankees, who have been looking for a left-handed bat off their bench, sent minor-league outfielder Marcus Thames to the Rangers.
The switch-hitting Sierra, 37, is batting .263 with a .398 slugging percentage and a .333 on-base percentage. Once one of baseball's most promising young players and a four-time All-Star from 1989-94, he became one of its biggest disappointments in the '90s and has slugged over .500 once since 1992.
Sierra played 96 games for the Yankees in 1996 under Torre, and he complained the manager had not been truthful about his playing time.
Torre said he and Sierra sat down at spring training a couple of years ago and patched up their differences.
Meanwhile, Yankees first baseman Nick Johnson said the stress fracture in his right hand isn't healing quickly, and he doesn't know when he'll return. Johnson was expected to miss four to six weeks after getting hurt May 14.
RED SOX-MARINERS TRADE: Seattle strengthened its bullpen by acquiring left-hander Matt White from Boston for minor-league outfielder Shelton Fulse.
ANGELS: Left-hander Chuck Finley rejected an offer to return to Anaheim as a relief pitcher, saying he prefers to start. ... Shortstop David Eckstein was scratched after injuring his left hand when struck by a batted ball during pregame warmups.
D'BACKS: Outfielder David Dellucci went on the 15-day disabled list despite his protests that he felt no ill effects from a concussion.
METS: Left-hander Tom Glavine, forced out of Thursday night's start in the second when his elbow flared up, is unsure whether he'll pitch Wednesday at Texas. "We're working with a timetable of 48 hours," he said.
REDS: Right-hander Pete Harnisch was released, leaving him unsure whether he'll continue his comeback from reconstructive elbow surgery. ... Centerfielder Ken Griffey was out of the lineup for the second straight game because of a virus.
RED SOX: Right-hander Tim Wakefield was hit by a pitch just above his right ankle in the third and left.
