BOSTON -- Boston Red Sox third baseman John Valentin underwent surgery on his left knee Thursday by a doctor who the club said it did not authorize.
Valentin's agent, Dick Moss, said Valentin returned to his New Jersey home after the surgery in New York by Dr. David Altchek, the team physician for the Mets. Valentin, who had surgery performed by Altchek on the same knee last November, is expected to miss the rest of the season.
The Red Sox said they had no information on Thursday's operation to correct a ruptured patellar tendon.
"Despite the club's efforts to coordinate the medical care, John Valentin went to a physician that was not authorized by the club to perform the procedure," Red Sox spokesman Kevin Shea said.
Moss said "I'm at a loss to understand" the team's statement.
"Nobody from the Red Sox, (general manager) Dan Duquette or anybody, has called me to indicate there is any problem," he said.
Shea refused to say whether the team was upset with Valentin's choice of doctors.
Dr. Arthur Pappas, the Red Sox team physician, had said Wednesday that he expected Altchek to perform the operation.
Moss said Altchek was authorized by the Red Sox to perform the surgery last November, when scar tissue around Valentin's patellar tendon was cleaned out. Altchek also repaired a small cartilage tear. He also has performed surgery on Boston pitcher Bret Saberhagen's right shoulder.
Valentin, who went on the disabled list April 10 with patellar tendinitis in his left knee, had started just eight games since he returned to the roster May 19.
The latest injury occurred in the second inning Tuesday night against Kansas City when he collapsed while charging a grounder by Carlos Beltran.
Moss said Altchek is one of the top three orthopedic surgeons in the country and is on a list agreed to by the owners and the players association of doctors to be consulted for second opinions.
"I sort of resent the fact that they say John did anything improper," Moss said. "It's not like John went to some fly-by-night guy. This is one of the leading guys in the country.
"I have no idea what they have in mind."
Valentin, 33, is in his ninth major-league season, all with the Red Sox. He has the longest tenure on the team and entered the season batting .283. This season, he batted .257 with two homers and two RBI in 35 at bats over 10 games.
He is signed through the 2001 season with a club option for 2002.