The Associated Press

NEW YORK - New York Mets catcher Mike Piazza will miss at least six weeks, and possibly the rest of the season, after tearing a groin muscle Friday.

"It is in the back of your mind. It's the ultimate fear," Piazza said Tuesday. "But I'm not looking at that right now."

Piazza saw team physician Dr. Andrew Rokito, who said the All-Star catcher had a Grade 3 strain - the most serious - with the muscle partially torn off the bone. Piazza will not need surgery.

When asked if the injury could be season-ending, Mets general manager Steve Phillips said: "It's possible. We don't know. We're leaving it as an indefinite period of time."

Piazza is the Mets' best hitter, batting .333 with a team-leading seven homers and 15 RBI.

The catcher, who is on crutches, will begin rehabilitation after the swelling goes down in about two weeks.

RED SOX: Pedro Martinez was listed as day-to-day after missing his start Tuesday against the Yankees because of a mild strain of a back muscle. Team physician Dr. Bill Morgan said "everything looked stable" during an MRI exam.

MARLINS: Catcher Ivan Rodriguez is expected to miss Florida's three-game series at Montreal after flying to Puerto Rico to tend to his ill mother-in-law.

YANKEES: Jose Contreras rejoined the team after working on his mechanics and confidence in four minor-league appearances. He had three appearances at Triple-A Columbus and one for Double-A Trenton.

Contreras, who was signed to a $32 million, four-year contract Feb. 6, was 1-0 with a 10.80 ERA in five relief appearances for New York.

• Yankees reliever Steve Karsay had surgery to repair a partial tear of his right rotator cuff and will miss the rest of the season. The team said Karsay, who has been out all season, is expected to be ready by spring training.