CUMBERLAND, Ga. -- A lot has been running through Sean Newcomb's mind the past two days.

The 23-year-old left-handed pitcher was called up for his Major League debut, but that debut didn't come until a couple days after he had gotten the call that he had made it to The Show.

"I think that was the worst part. The past two days, sitting there and thinking about what everything was going to be like and not knowing what to expect," Newcomb said following his debut on Saturday at SunTrust Park. "Once I got in this morning, I just kind of relaxed and was ready to go."

If he was nervous, it didn't show. Newcomb came out looking like a veteran against the New York Mets on Saturday. The first inning, he struck out the side. The first was Juan Lagares missing on his marquee curve ball. His fastball blazed by the next batters. As he walked off the field after a perfect inning, that's when, he admitted, it began to sink in that he was a big leaguer, and he belonged.

Newcomb pitched 6.1 innings and threw seven strikeouts. He had four hits and two walks.

His only error was on a ball hit back to him by Asdrubal Cabrera that bounced off his toe and into his glove. The game sped up slightly for the rookie, and his throw to second sailed on him and went into the outfield. The next at bat, T.J. Rivera hit a sacrifice fly to center to drive in Wilmer Flores.

"Couldn’t have really pictured it to go any better than it did. Other than that one throw to center field," Newcomb joked.

Newcomb (0-1) was credited with the loss despite the strong start. After Flores had an RBI on a sacrifice fly in the eighth, Yoenis Cespedes hit a grand slam in the ninth off Luke Jackson and led the Mets to a 6-1 win. Brandon Phillips' home run in the eighth was the Braves' only run.

Catcher Tyler Flowers didn't know what to expect from Newcomb. He hadn't seen him since spring training. He noted his slider had improved since then, and he was developing a change-up. He started to see tendencies of his strong command in the bullpen before the game. But Flowers really likes how Newcomb carries himself.

"Doesn’t show a lot of emotion. Doesn’t get high, doesn’t get low. Just kind of does what he can do, take care of what he can control, and he did a great job of that," Flowers said.

There's been a lot of talk about the Braves' young pitchers, like Newcomb. Fans are desperate to see what they have to offer after recent outings by Braves pitchers, such as Bartolo Colon's last start where he gave up eight earned runs in less than four innings.

There are several other young hurlers on the way up in the months to come.

"If they all do that, we’ll be just fine. Obviously there’s a lot of talk over the last couple years about [young pitchers]," Flowers said. "Hopefully that’s the first head of the next rotation coming in. I think we’ll be in a good spot."

Manager Brian Snitker said he will make a decision in the next couple days if Newcomb will stay in the rotation.

"Very encouraging. The whole thing was," Snitker said. "It’s refreshing. It’s nice to see, like we’ve been talking about, young guys, to see one of them. He was just very in command of everything that he was doing and that was a very impressive outing."

Newcomb isn't anxious to hear if he'll get another start soon. He was just happy to get this one under his belt.

PHOTOS | SunTrust Park