Edgin Edgin, who will wear No. 66, gives the Mets a second left-hander in the bullpen alongside Scott Rice.
His velocity down, Edgin had been among the first cuts of spring training from big-league camp.
He had just been in Charlotte and away from Triple-A Las Vegas for the birth of his child.
Edgin, 27, posted a 3-0 record, two saves and a 4.97 ERA in 17 appearances with the 51s. He has contributed seven straight scoreless appearances, although opponents have a .327 batting average against him for the season and he has allowed 16 hits and 11 walks in 12 2/3 innings.