Terry Collins said Mejia could land in the bullpen if a pitcher likes Daisuke Matsuzaka or John Lannan beats him out for the last rotation spot.
Mejia appeared in five games with the Mets in 2013, posting a 2.30 ERA and 1.171 WHIP over 27 1/3 innings. He has 32 relief appearances in the majors under his belt, with a 3.23 ERA and 1.565 WHIP. He last pitched in relief in 2012, with the bulk coming way back in 2010.
He went on the disabled list late in the 2013 season and had surgery to remove bone spurs in his elbow.