by Ken Rosenthal

Dempster, 31, plans to test the open market, major-league sources say. He filed for free agency on Friday, and does not intend to sign with the Cubs before their exclusive negotiating period with him expires on Nov. 13.

The prevailing assumption in baseball is that the Cubs will re-sign Dempster, a right-hander who went 17-6 with a 2.96 ERA last season while starting full-time for the first time since 2002.

Dempster's return, however, no longer is a given.

While the Cubs remain interested in retaining Dempster, an 11-year veteran, the pitcher first will entertain bids from other clubs. He conceivably could receive four-year offers on the open market, an important consideration if the Cubs only are willing to give him three.

The Cubs are in a similar position with closer Kerry Wood, who also has filed for free agency. Wood, like Dempster, is close with Cubs general manager Jim Hendry. But both pitchers could find that other teams are willing to pay them more than the Cubs.

If the Cubs fear losing Dempster, they could take a more serious look at a trade for Padres right-hander Jake Peavy, a pitcher in whom they long have had interest. Peavy, who holds a full no-trade clause, has identified the Cubs as one of his preferred teams.

The lack of quality starting pitching on the market virtually ensures that Dempster will secure the biggest contract of his career. He is coming off a three-year, $15.5 million deal in which his highest salary was $5.5 million.

Most of the high-revenue clubs — including the Mets, Yankees, Red Sox, Dodgers and Angels — are trying to add starting pitching. Dempster, after succeeding under pressure in Chicago, presumably would be attractive to the New York teams, among others.

The question with Dempster is whether he could repeat his performance of 2008, his first converting back to starting after three seasons as the Cubs' closer. He underwent elbow surgery in '03, but his only injury since then was a strained left oblique in '07.