Jason Isringhausen's first relief appearance will set a franchise record for gap between pitches thrown for the club, according to the Elias Sports Bureau.
Isringhausen last threw a pitch with the Mets on July 31, 1999, before he was traded to Oakland.
The current record holder is Bob Miller, who went 10 years, 362 days -- from Sept. 29, 1962 to Sept. 26, 1973 -- between Mets appearances.
David Cone is next at 10 years, 224 days (8/23/92 to 4/4/03).
As far as MLB goes, it would be the longest gap since Doug Brocail returned to the mound for San Diego 11 years, 346 days after his last appearance, on July 14, 2006.
Meanwhile, a clarification:
Isringhausen can refuse an assignment to the minors in his new contract, and would still be obligated to receive his $500,000 salary. That differs from the original language.