Frank Viola is resting comfortably with his family, the Mets announced Wednesday, after the East Meadow native underwent heart surgery.
"From that standpoint, we're all extremely pleased obviously for Frank and his family," general manager Sandy Alderson said.
After drawing raves for his work at Class-A Savannah, Viola was promoted by the Mets to Triple-A Las Vegas, where he was to serve as the pitching coach. It's unclear when he'll be able to return.
"He certainly wants to be back," Alderson said. "But I think we'll let the doctors dictate exactly when he does come back. When he's ready and he's able, I'm sure he'll be out there. But we want to make sure he's fully recovered from this surgery first."
Chris Young's debut lasted half an inning.
Young left Wednesday night's game against the Nationals when he aggravated the right quad strain that forced him to miss the opener on Monday. "It feels like a bad dream," said Young, who will be re-evaluated today. "It's the last way you want to [start] with a new team. I feel terrible about it."
Young felt a grab in his quad when he gave chase on a foul ball to leftfield. He finished the inning before he was kept from returning to the field in the second. He left the game with what the team called quad tightness.
Young initially suffered the injury in last Saturday's exhibition finale against the Blue Jays in Montreal.
Jonathon Niese (left elbow inflammation) said he's "pretty confident" about starting on Sunday against the Reds. "I didn't feel anything, fully normal," Niese said one day after a simulated game. He plans to throw a bullpen session Thursday.