"That's the first time I've seen him throw. He looks great, man," Andy Pettitte said. "The ball just explodes coming out of his hand."
Pettitte arrived in camp on Monday as a guest instructor, and though he said he has no interest in becoming an unofficial pitching coach, he will be interested to track Banuelos' progress.
"You never know what anybody's going to do until they get to the big league level and they go out there and they are kind of battle-tested," Pettitte said. "You can talk about people all you want, but he looks great. His stuff looks great.
"He's just got a live arm, and from what I hear, he's got a chance to do some good things. I haven't even had a chance to meet him yet, but I'll try to introduce myself to him and talk to him. If I can do anything to help him, I would love to be able to do that, that's for sure."
Banuelos, who turns 21 next month, was a combined 6-7 with a 3.75 ERA in 27 starts at Double-A Trenton and Triple-A Scranton/Wilkes-Barre last year. Banuelos said that he needs to cut down on his walks, having permitted 71 in 129 2/3 innings.
"I think I didn't do like I wanted," Banuelos said. "So now I know what mistakes I did, I don't want to do again, especially command of my fastball. It's so important to command the fastball, control the fastball. I don't want any more walks."
Yankees manager Joe Girardi said that he has been impressed thus far by both Banuelos and right-hander Dellin Betances.
"I think both of them are improved, when you look at both of these young kids," Girardi said. "I think they're more consistent in the strikes they throw, in their mechanics. The quality of the pitches they throw -- I can see it."