The left-handed reliever made his Major League debut in the seventh inning of New York's 6-0 loss to the Blue Jays at Rogers Centre. It didn't go exactly as he'd hoped, as he allowed three walks and two earned runs in two-thirds of an inning, but Dunn said he tried to take it all in.
"It's the first time, and everyone says it gets better," Dunn said. "I hope so. I've got stuff I've got to work on, and just throwing strikes is the biggest thing."
A converted outfielder who switched to pitching in the Yankees' farm system three years ago, Dunn retired the first batter he faced in the big leagues, getting Rod Barajas to fly out to left field.
But Dunn walked Travis Snider and Joe Inglett, drawing pitching coach Dave Eiland to the mound for a breather. Dunn got John McDonald to hit into a forceout, but then walked Marco Scutaro before being relieved by Edwar Ramirez, who surrendered a two-run double to Aaron Hill.
"It's unacceptable, especially two of them being lefties," Dunn said. "I pride myself [on] facing lefties and to walk two of them, I'm pretty disappointed."
Yankees manager Joe Girardi said that he saw good signs from Dunn, who was 4-3 with two saves and a 3.31 ERA in 38 relief appearances with Scranton/Wilkes-Barre and Double-A Trenton this season, allowing just two of 12 inherited runners to score.
"I thought he threw some good sliders," Girardi said. "He's got good velocity. Obviously, he didn't have the command that he wants to have. It's the first game, and there's a lot of emotions that go into that first game that you have to learn how to control. I'm anxious to get him in there again."
Dunn's 27.00 ERA won't last forever, but he said that he will try to keep the mental snapshot he took after jogging in from the bullpen.
"Probably before I threw even my first pitch," Dunn said. "Jorge [Posada] met me out on the mound and gave me the ball. I stepped back and tried to take it all in, and then I was like, 'All right. Let's pitch.'"
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.