With only two games as a Yankee under his belt, the 27-year-old has added two lineup cards and two baseballs to his souvenir shelf.
There's a card and ball from Duncan's first Major League hit -- an RBI single off Brian Stokes in the eighth inning of Friday's game against the Devil Rays. And there's one of each to account for Duncan's first career home run, in Game 1 of Saturday's day-night doubleheader.
After bouncing around the Minors for more than six years, Duncan received his first curtain call at Yankee Stadium after hitting a two-run homer in the eighth inning. He came back out of the dugout to the applause of the standing crowd, lifting his helmet from his head and holding it in the air as he turned to take it all in.
"You get goosebumps, you know," Duncan said. "It's just one of those things where you're kind of frozen. It's your little moment right there, that brief second. It's something that you can always bring with you."
Andy Phillips, who crossed the plate ahead of Duncan, was the first to congratulate him -- and the first of many Yankees to feel the sting of Duncan's big hand in a hard-hitting high-five.
"It was an awesome experience until he slapped me in the hand and nearly knocked me down," Phillips said.
Manager Joe Torre was happy for Duncan, too, but was more prepared.
"This kid has so much energy," Torre said. "When he hit the home run, [bench coach] Don Mattingly was standing next to me and said, 'Don't let him high-five you when he comes in.' I just saw him tearing down from third base."
It was only fitting that Phillips was the one waiting when Duncan finished rounding the bases. Earlier this season, the two played together for Triple-A Scranton/Wilkes-Barre, and Duncan sees Phillips as a sort of older brother.
"It was perfect," Duncan said. "I can't tell you how much I look up to him. He was one of my closest buddies in Scranton when he was down there. Even here, when I first got here, he's been there for me."
It was Phillips whom Duncan credited following the game, pointing out that his teammate helped set up the moment. Even so, Phillips knows that Duncan's recent success has been well deserved.
"He definitely has some baseball in his blood," Phillips said. "He has some experience to draw back on. With the kind of year he was having [in the Minor Leagues], he certainly earned the opportunity by his hard work."
The son of Cardinals pitching coach Dave Duncan and the older brother of St. Louis outfielder Chris Duncan, Duncan does indeed have baseball in his blood. Throughout his career, he has gained valuable advice from his father and brother, and has used it to work his way up through the Minors.
With Scranton this year, Duncan batted .295 and led the team in home runs, with 25, and RBIs, with 79. Now he's using his first few Major League at-bats -- home run included -- to break himself into the new scene.
"Dad's always taught me, as soon as that game's over with, enjoy the moment and put it behind you, because things happen so fast in this game," he said. "As soon as you start feeling comfortable you get used to it, and you can just relax. You feel a part of things, and it allows yourself to really be yourself."
Duncan's debut couldn't have come at a better time for the Yankees. On Saturday, his two RBIs added a nice cushion to the team's lead over the Devil Rays, putting the Yankees up, 7-3.
"He's always around, and then all of a sudden, he blossoms here, and you see his personality a little bit more than you did in the spring," Torre said. "He can certainly scare people -- not just with handshakes -- but you miss your spot, and he's going to hurt you."
Lauren Kobylarz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.