New York will pay a buyout worth $500,000, and Niese will be a free agent.
The Mets traded the left-handed pitcher to the Pittsburgh Pirates last offseason for Neil Walker, a move Pirates general manager Neal Huntington admitted he regretted. He was then sent back to New York for Antonio Bastardo.
Unfortunately, he struggled in both locations, posting a 4.93 ERA in Pittsburgh before allowing 14 earned runs in 11 innings with the Mets.
It was altogether the worst full year of his career, ending with a 5.50 ERA with an FIP of 5.62, per Baseball-Reference.com.
While the 30-year-old pitcher has had better days in the past, including a 13-win season in 2012 when he posted a 3.40 ERA, he clearly wasn't worth the $10 million it would have cost to keep him on the roster.
Niese is now a free agent and will hope to take advantage of a light pitching market around the league. He has been a quality starter in the past, posting a 4.07 career ERA in 211 appearances (197 starts) with a 69-68 record.
If given a chance, he can provide depth to a team's rotation or a long reliever out of the bullpen.