Ishii, 31, was with the Mets for the first four months of the season as a stand-in for Steve Trachsel before being optioned to Norfolk on Aug. 6, going 3-9 with a 5.06 ERA in 19 starts.
Hamulack, 28, was signed by the Mets as a minor league free agent on Dec. 28, 2004, and has had a successful comeback from arthroscopic elbow surgery in the organization.
After falling just shy of making the Red Sox roster out of spring training in 2004, Hamulack punched his ticket to the big leagues by going 2-2 with a 1.26 ERA and six saves at Binghamton (AA), then going 3-1 with a 1.02 ERA and six more saves in 28 games at Norfolk (AAA). He was originally to be selected to the Mets' roster last week in Arizona, even meeting the club at their hotel, but was sent back to the Tides when the team opted to keep Mike Jacobs as an active player.
Takatsu, 36, began the season as the closer for the Chicago White Sox, but flopped badly after a case of dead arm and was released.
Last year's runner-up American League Rookie of the Year, Takatsu was 1-2 with a 5.97 ERA and six saves in 31 games with Chicago and signed with the Mets as a free agent on Aug. 12. He made seven appearances (one start) with Norfolk, going 0-1 with a 3.38 ERA.