New York Yankees manager Aaron Boone is taking an immediate medical leave of absence after having surgery Wednesday to get a pacemaker, the team announced.
The team said that Boone's surgery went "as expected" and that he would spend the night at St. Joseph's Hospital in Tampa, Florida, to rest and recover. Boone was "in good spirits," the team said.
On Thursday, a team source told ESPN's Marly Rivera that Boone was released from the hospital and is doing "very well."
General manager Brian Cashman said Boone could return to the team in two to three days.
The 47-year-old, who had open-heart surgery in 2009, said in a statement that he has had mild symptoms of lightheadedness, low energy and shortness of breath over the past six to eight weeks. He said further tests in New York before spring training indicated he had a low heart rate, necessitating the surgery.
"My faith is strong, and my spirits are high," Boone said. "I'm in a great frame of mind because I know I'm in good hands with the doctors and medical staff here. ... They are confident that today's surgery will allow me to resume all of my usual professional and personal activities and afford me a positive long-term health prognosis without having to change anything about my way of life."
Boone, entering his fourth season as manager of the Yankees, said he looks forward "to getting back to work in the next several days."
Bench coach Carlos Mendoza took over as acting manager for Wednesday night's exhibition, a 4-1 win over Toronto in Tampa.
Mendoza, 41, was a minor leaguer mostly with San Francisco and the Yankees from 1997 to 2009 and is starting his 13th season working for the Yankees. He joined the major league staff as quality control and infield coach under Boone in 2018 and succeeded Josh Bard as bench coach for 2020.
"The mindset doesn't change,'' Mendoza said. "We have a really good group of coaches here and really good personnel that are going to continue to get these guys ready to play the regular season."
Boone recorded a video that was given to players.
"He just wanted them to continue to get our work in, continue to do [things] the right way, the same way we've been doing here, and that made all of us feel a lot better," Mendoza said of the players' reaction.
Brett Gardner, the Yankees' senior player, said the video helped comfort players. He said Boone had mentioned a few days ago when passing in a hallway that he was feeling tired.
"I think it was a shock to most of us,'' Gardner said. "I think his first concern was making sure that we would continue to go about our business the right way with him being gone and, obviously, to kind of ease our minds that we weren't too overly concerned about him and this procedure.''
"It's a necessary step,'' Cashman said of Boone's surgery. "It's something that's not avoidable and needs to be taken care of, but he has no fear and I know he's just in great hands and it's just a temporary timeout. He looks forward to getting back to doing what he does best and doing what he loves, which is baseball.''
Cashman said that, at first, he was alarmed by the news, but was "comfortable" upon talking to Boone about the surgery.
"When you hear 'pacemaker,' it kind of sets off a lot of alarms of concern," Cashman said. "No one's going to do more research than the person that's going to be going through this, and I felt so comforted by the way he communicated with me on it that he put me at ease."
Yankees owner Hal Steinbrenner said "the thoughts of the entire organization are with Aaron and his family" in a statement released by the team.
"Aaron leads our players, coaches and staff with a rare combination of work ethic, intelligence and a genuine concern for others," Steinbrenner said. "Our only priority at this time is Aaron's health and well-being, and we will support him in every way throughout his recovery."
Boone played in the major leagues from 1997 to 2009. He was an All-Star for the Cincinnati Reds in 2003 shortly before getting traded to the Yankees. Later that year, his 11th-inning home run off Boston's Tim Wakefield in Game 7 of the AL Championship Series won the pennant for New York.
Boone is a third-generation major leaguer; his grandfather Gus, father Bob and brother Bret also played in the big leagues, and his nephew Jake is a minor leaguer in the Washington organization.
The Associated Press contributed to this report.