MLB Network's Jon Heyman added the the total value of the contract will be for $15 million over two years.
The Twins brought up May as a starting pitcher late in the 2014 season. The right-hander struggled in his first three seasons in the rotation and as a reliever. He had a 5.14 ERA in 102 appearances from 2014-16.
After missing the 2017 season due to Tommy John surgery, May came into his own upon returning in 2018. The 31-year-old has posted a 3.19 ERA with 153 strikeouts and 84 hits allowed in 113 games over the past three seasons.
Aaron Gleeman of The Athletic noted in October that some of May's underlying stats from 2020 suggest he could improve on last season's 3.86 ERA:
"Much like last season, a few costly homers kept May from securing a consistent late-inning role, logging 62 percent of his work before the eighth. However, he dominated more than a mediocre 3.86 ERA suggests, striking out 39.6 percent of his batters faced for the best strikeout rate in Twins history. May’s swinging-strike rate jumped to 18.5 percent, second-best among AL relievers."
The Mets ranked 18th in MLB last season with a 4.60 ERA and 22nd with 0.5 FanGraphs wins above replacement from their bullpen.
When the deal gets finalized, May will join Edwin Diaz and Jeurys Familia as late-game options for Mets manager Luis Rojas in 2021.