The 33-year-old utilityman was picked up in exchange for Minor League catcher Chase Weems and packed his bags almost immediately, flying to Chicago from Cincinnati to meet the team for Saturday's afternoon contest.
"I thought I made it through [the Trade Deadline], because I was getting ready for batting practice, and then they called me in," Hairston said.
"It was a pleasant surprise, but at the same time, I got real close with a lot of the players there. Great people, young guys. They're on the fast track."
Yankees manager Joe Girardi wasted little time getting Hairston involved with his new squad, starting him in left field and batting him eighth on Saturday, as the Bombers played the third game of four against the White Sox.
"[Hairston] was in early this morning, and we had a chance to talk," Girardi said. "I'm glad he's here. He's going to provide a lot of versatility for us. He's played six positions, so I won't hesitate to put him anywhere."
While Hairston couldn't keep the Yankees from suffering a 14-4 loss, their third straight, he at least had an productive afternoon. Hairston reached base in his first three at-bats wearing a New York uniform, walking and scoring on a Mark Teixeira single in the third inning and singling in the fourth off Chicago's John Danks.
Hairston also drove in a run with a fielder's choice in the sixth, dropping a bases-loaded flare in front of White Sox left fielder Carlos Quentin, who deked Jorge Posada at second base into thinking the ball would be caught before firing to third base for the putout.
On defense, Hairston also flipped into the seats down the left-field line while chasing a fifth-inning foul ball hit by Quentin, banging his right hip into a padded railing and going into the stands.
To make room for Hairston on the Yankees' roster, Shelley Duncan was optioned to Triple-A Scranton/Wilkes-Barre after spending just one game in the big leagues. Girardi said that Duncan, 29, could return as a September callup.
Part of Hairston's appeal is that he has the ability to play everywhere except catcher; Hairston was hitting .254 with eight home runs, 27 RBIs and seven stolen bases in 86 games at the time of the trade.
"I try to really not overanalyze it, whether I'm playing third one day, left or center," Hairston said. "I just try to do my job that particular day and make the routine plays when I can.
"I've really worked hard at it; it's not real easy. It's taken some time, but I pride myself on being able to play just about anywhere."
With the Reds this season, Hairston had played 33 games at third base and 31 games at shortstop, but had also appeared at second base and all three outfield positions. That makes Hairston likely to see some time in center field, with Brett Gardner on the disabled list with a fractured left thumb.
"Joe is going to use his whole 25-man roster, and like I told him, whatever you need me to do, I'll come over and do it," Hairston said. "I'm coming to a first-place team, and I just want to fit in here and do my part."