In 2008 the Twins traded their ace to the Mets for four players. The Mets signed him to a seven year $137.5 million contract. New York looked forward to having one of the best pitchers in baseball.
In the first year Santana pitched very well. His record was 16-7 but the bullpen blew seven saves in games he could have won. His 2.53 ERA was the lowest in the majors and his 206 strikeouts set a Mets single season record.
That ended up being his only good season with the Mets. A series of injuries allowed him to only pitch in three more seasons with a combined record of 30-27.
After pitching only 3 1/2 years of his contract, the Mets released him paying a $5.5 million buy out to avoid paying the last $25 million. It also reduced the Mets from a 7 year contract to 6 years,
The Mets thought they would have an Ace pitcher for 7 years. Instead they got one good year. Every other year he was injured for part of the year or he missed the whole season. They paid 6 years of his contract for those results. It did not meet expectations of the team or the fans. It was a Swing Badder contract.