NEW YORK - While the Boston Red Sox prepared for their victory parade, their former All-Star shortstop, Nomar Garciaparra, filed for free agency.

Until he was dealt to the Chicago Cubs on July 31 as part of a four-team trade, Garciaparra had spent his entire career - 8½ years - with the Red Sox, who beat St. Louis Wednesday to complete their World Series sweep.

Garciaparra has said he would consider returning to Chicago, and general manager Jim Hendry has already spoken with his agent, Arn Tellem. But Garciaparra also wants to test the free agent market for the first time in his career.

"I'm going to experience something I never experienced in the offseason," Garciaparra said on the last day of the season. "Like I said, this is one of the places I'll consider. No question."

But there likely will be plenty of other suitors for the five-time All-Star and two-time AL batting champion. Though Garciaparra was slowed by injuries to his Achilles' tendon, left wrist and groin - he played only 81 games - he hit .308 with nine homers and 41 RBI for the Red Sox and Cubs.

Garciaparra batted .321 in 38 games with Boston and .297 in 43 games with the Cubs.

In their first move since winning their first Series title since 1918, the Red Sox exercised a $2.5 million option Friday on third baseman Bill Mueller instead of paying a $500,000 buyout.

"We have tremendous ownership. We have a great fan base. We have a great nucleus. We have a lot of resources," Mueller said Wednesday night. "Maybe we can contend for this every single year."

The 2003 AL batting champion hit .283 with 12 homers and 57 RBI this season. Mueller, limited to 110 games by arthroscopic surgery on his right knee, had the tying single against the New York Yankees' Mariano Rivera in the ninth inning of Game 4 of the AL championship series, starting Boston's comeback from an 0-3 deficit.

Boston has up to 16 players eligible for free agency, including pitchers Terry Adams and Pedro Astacio, who were among 58 players to file Friday, raising the total to 123 of the 215 potentially eligible.

Cardinals shortstop Edgar Renteria filed along with catcher Mike Matheny and outfielder Ray Lankford. Re-signing Renteria, 29, is expected to be one of the Cardinals' top priorities. He batted .287 with 10 home runs and 72 RBI this season.

Florida All-Star third baseman Mike Lowell, who could have opted out of his contract, agreed to a new contract with the Florida Marlins that guarantees the remaining $25.5 million his previous deal called for.

Cincinnati exercised first baseman Sean Casey's $8.5 million option for 2006.

"The fact that they picked up the contract shows me they want me to be here," he said.

Cincinnati shortstop Barry Larkin and Cleveland shortstop Omar Vizquel filed for free agency along with Colorado third baseman Vinny Castilla, who declined a $2.1 million mutual option after hitting 35 homers in his first season back with the Rockies and leading the NL with 131 RBIs.