Manaea, who struck out 184 in a career-high 181.2 innings, was excellent for the Mets in the second half after changing his delivery and arm slot to mimic Chris Sale. In the playoffs, he made four starts, going 2-1 with a 4.74 ERA.
The Mets will have three holes to fill in their rotation now with Manaea officially joining Luis Severino and Jose Quintana as free agents.
Manaea is 77-62 over his nine-year career with a 4.00 ERA. Before his one season in New York, he played six years in Oakland and one each in San Diego and San Francisco.