Mejia told the Mets he wanted to finish the reason before having surgery. He is taking anti-inflammatory medication, according to the website.
Mejia will be activated from the DL to start for the Mets against Washington on Friday in the first game of a doubleheader.
He hasn't pitched in the Major Leagues since Sept. 30 of last season, when he allowed four runs on six hits with two walks and three strikeouts in Atlanta.
Chris Iseman is an associate reporter for MLB.com. David Wilson is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.