Acquired from the Florida Marlins on Nov. 13, 2008, in a trade for Minor League pitcher Jose Ceda, Gregg was bumped from the role in mid-August by Marmol, who will be the Cubs closer in 2010.
Gregg was classified as a Type A free agent, which means if another team signs him, the Cubs would receive a first-round pick as compensation. That's the case unless the signing team is selecting from picks No. 1-15, and in that case, the Cubs would receive a sandwich pick between the first and second rounds.
In 72 games this season, Gregg, 31, finished with a 4.72 ERA and 23 saves. He was shut down on Sept. 29 because of a sore rib cage. All of his seven blown saves came on the road.
On the plus side for the right-hander is that 2010 will be his second year after arthroscopic knee surgery, which he had after the '08 season. He has appeared in at least 72 games in three straight seasons.
The only other potential free agents on the Cubs who have yet to file are pitchers John Grabow and Chad Fox. Reed Johnson and Rich Harden filed on Thursday. A player must file within 15 days after the World Series is over. The Cubs retain exclusive negotiating rights during that 15-day period.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.