"If I recall, I think they booed," Headley told MLB.com by phone on Tuesday after learning that he had been traded to the Yankees as part of a three-player deal. "Their fans are very passionate."
He's about to find out as, after three years of rumors of him being dealt before or on the July 31 non-waiver Trade Deadline, Headley was finally traded away from the only organization he's ever known.
The Padres on Tuesday sent Headley and $1 million to the Yankees for infielder Yangervis Solarte and right-handed pitcher Rafael De Paula.
"I'm not surprised," Headley said from Chicago, where the Padres were preparing to play the Cubs. "You understand the circumstances ... and you know there's a good chance it can happen. But on the same token, and I've dealt with it in the past and nothing has happened, it's weird.
"You never think this day is going to come."
That's probably because this is the only organization Headley has ever known. He was taken with the 66th overall selection (second round) out of the University of Tennessee in the 2005 Draft and reached the Major Leagues, in an eight-game stint, two years later.
It wasn't until 2009 when he got his first chance to play on an everyday basis for the Padres.
Headley, 30, finishes his Padres career ranked among the all-time club leaders in several notable categories, including games (908, sixth), at-bats (3,286, fifth), hits (873, fifth), doubles (186, fourth), home runs (87, eighth), RBIs (401, 10th), walks (377, seventh) and strikeouts (844, first).
"I've seen Chase grow up. From the time he was drafted, through his time with the Minors. He got to the Majors in 2007, my first year as a manager. I've seen him perform on the field, lead the league in RBIs, get a Gold Glove, get married, have children," Padres manager Bud Black said Tuesday.
"All of those things that happened over the course of a period of eight seasons. To say farewell is a tough one. He's meant a lot to the organization. What he's done off the field, especially the last couple of years as he settled into being a Major League player. He's been a good Padre."
Headley's breakout season came in 2012, when he had a monster second half, with most of the damage coming after the anxious moments as the Trade Deadline passed. In recent years, he said, Headley did much better in handling the stress of not knowing if he was staying or going.
He also won a Gold Glove in 2012 for his work at third base.
Then there was consternation over getting a contract extension worked out.
Headley, on numerous occasions, said he wanted to remain with the team. The Padres, who have had three ownership groups since Headley reached the big leagues, have often said they wanted to keep Headley in San Diego.
But the two sides were far apart in terms of what they considered was fair in terms of contract length and average annual value. So they agreed at that time to walk away.
All of that was water under the bridge on Tuesday for Headley, who admitted that his head was spinning as he prepared to get from Chicago to New York to join his new team.
"It's bittersweet," Headley said. "One one hand, there's not many people in the game who get to play in one organization for as long as I did. I loved every second in San Diego. All positive memories. But on the same token, I'm excited to move on to a team in a [postseason] race right now."
Headley said he leaves San Diego with one regret -- not being able to get to the postseason for the only manager he's ever played for. The Padres came close in 2007, losing to the Rockies in Game No. 163, then missing the postseason by one game in 2010.
"That was very tough," Headley said of his conversation Tuesday morning with Black. "I can't say enough positive things about how Buddy has been as a manager and a manager to me. I can't imagine it gets any better for me. We were both a bit emotional. It was a difficult conversation. He's meant so much to me. I wish we could have won more for him while we were there."