Willie Harris left during Wednesday's game to fly to New York after his wife Trey unexpectedly went into labor only five months into her pregnancy, Terry Collins said. Harris was able to get a flight from Detroit to New York on Wednesday night.
The Mets placed Harris on paternity leave, which lasts one to three days.
"It's pretty early for the baby, so I hope she's OK," Collins said. "We're thinking of him and her."
Fernando Martinez is being promoted from Triple-A Buffalo. He was hitting .266 with six homers and 23 RBIs in 158 International League at-bats this season, and had recently missed a week because of a flare-up with his arthritic right knee.