General manager Rick Hahn said LaRoche told his teammates in a clubhouse meeting Tuesday morning and was asked to reconsider his decision, which Hahn characterized as a "personal decision."
Hahn said he was not expecting the news but added that after "extensive conversations with him, between us and his coaches and he and his teammates, you would have to be respectful and understand his perspective."
LaRoche, 36, signed a two-year deal for $25 million with the White Sox a year ago. But he struggled in 2015, batting .207 with 12 homers. A first baseman-turned-designated hitter, LaRoche hadn't played since early this month because of back spasms.
LaRoche said he would address his decision in more detail later this week.
"I want to sleep on it again," LaRoche said, according to the Chicago Tribune. "I didn't come in yesterday because I wanted to make sure it was the right move and make an emotional decision. I'm confident it is.
"Out of my respect for these guys and Rick, they asked me to give it a day or two to confirm."
LaRoche also took to Twitter later Tuesday afternoon.
Thank u Lord for the game of baseball and for giving me way more than I ever deserved!#FamilyFirst— Adam LaRoche (@e3laroche) March 15, 2016
White Sox manager Robin Ventura said he tried to talk LaRoche out of it.
"He made his mind up, and I respect him for that," said Ventura, who noted that he had talked to LaRoche on Monday night but didn't know he was going to tell the team Tuesday.
As for the reaction from LaRoche's teammates, Ventura said the team wants it "to be more about LaRoche than anything else."
"They respect this guy a lot. He gets the respect, so when he says it, it takes a while for it to sink in for guys," Ventura said.
Newly minted White Sox third baseman Todd Frazier had his locker next to LaRoche's this spring and said he's going to miss him.
"I didn't hear anything about it, came in today, said he was retiring, that was about it," Frazier said.
Hahn didn't sound as though he expected LaRoche to have a change of heart, saying he was "very certain as to the course of action he wanted to take."
Hahn added, "Given the outpouring he heard from his teammates as well as those of us around the office, there's certainly the potential that maybe he does change his mind."
LaRoche also had played for the Washington Nationals, Atlanta Braves, Pittsburgh Pirates, Arizona Diamondbacks and Boston Red Sox. Over his career, he had a .260 batting average and 255 home runs. He had 100 RBIs in both 2010 and 2012 and hit a career-high 33 homers in 2012.
Los Angeles Dodgers shortstop Jimmy Rollins was well acquainted with LaRoche, having played against him for many years when Rollins was with the Phillies and LaRoche with their rival National League East teams. Rollins was on hand Tuesday as the White Sox beat the Dodgers 8-6.
"Every time I'd get on first base, he'd say, 'We need to play together,'" Rollins said. "I was looking forward to it. ... I've enjoyed playing against him all these years in the NL East. I didn't like to see those (homers) he was hitting off of us. He's just one of those guys that you watched because everything was so effortless."
Rollins, however, seemed to understand LaRoche's decision.
"Once a guy makes his mind up, it's made up," he said. "If you can get to him before that point, your job is just to listen. And he's been around for a while, obviously battling some injuries, and all those things weigh in."
LaRoche and his brother Andy, a minor leaguer, followed in the footsteps of their father, Dave, who was a pitcher.
The Associated Press contributed to this report.