Pittsburgh received pitchers Miguel Yajure and Roansy Contreras, infielder Maikol Escotto and outfielder Canaan Smith in the trade, which has been announced by both teams.
Taillon, 29, was the No. 2 overall draft pick in 2010 and was a 14-game winner for the Pirates in 2018. But the hard-throwing right-hander appeared in just seven games in 2019 and missed all of last season while recovering from Tommy John surgery on his pitching elbow.
Taillon, who has spent his entire professional career in the Pirates' organization, tweeted Sunday that it was a "bittersweet day" for him.
Bittersweet day for me over here! Trying to process everything- have SO much to say to the city of Pittsburgh and my teammates. Also have SO much to say about this incredible opportunity and to the city/fans in New York. Thanks to everyone that has reached out! More to come soon— Jameson Taillon (@JTaillon50) January 24, 2021
Taillon and Kluber, if healthy, could provide the Yankees with much-needed experience and depth in their rotation behind ace Gerrit Cole.
Besides Taillon and Kluber, the other candidates for the Yankees' rotation include left-hander Jordan Montgomery, who has appeared in just 12 games since his 2018 Tommy John surgery; youngsters Deivi Garcia and Clarke Schmidt; former All-Star Luis Severino, who missed all of last season because of Tommy John surgery; and Domingo German, who also missed the entire 2020 season while serving a suspension under Major League Baseball's domestic violence policy.
Taillon is on schedule to return this year after recovering from the August 2019 operation, which was the second Tommy John surgery on his right elbow. Pirates general manager Ben Cherington said they weighed "comparing what was on the table now to what we felt like could be down the road given a sort of reasonable expectation of a return and performance. And we just felt like this made sense for us right now."
Taillon's departure follows a deal earlier this month that sent right-hander Joe Musgrove to San Diego as part of a three-team trade that brought five prospects to Pittsburgh.
Since Cherington was hired as GM in November 2019, he has also traded first baseman Josh Bell and outfielder Starling Marte. Following the end of the season, the Pirates failed to offer a contract to Trevor Williams, a third member of their rotation last season, and declined a team option on Chris Archer, who missed last season following surgery to correct thoracic outlet syndrome.
"You've got to be willing to make decisions like this to add talent we're going to need to get this thing where we want to get it," Cherington said. "We're probably shifting some energy at this point now back toward adding to the team between now and spring training or adding or between now and season."
Still, he admitted: "We'll definitely keep the phone on" to listen if teams have interest in other players.
As for the Yankees, the trade also reunites a pair of former teammates in Taillon and Cole, who were both highly touted prospects in Pittsburgh's organization and played together with the Pirates in 2016 and 2017.
Yankees manager Aaron Boone had asked Cole about Taillon after New York had engaged Pittsburgh in trade talks.
"I told them, 'If you are going to bet on somebody, if you are going to go to battle with someone, that Jameson is the guy you want next to you'," Cole told the New York Post. "He is not fazed. He always makes people around him better. He is one of the most resilient people I have ever known."
Taillon told the Pittsburgh Post-Gazette that he's "super excited" to be reunited with Cole.
"I'm excited. We used to dream of coming up through the Pirates system together and doing some great things. Unfortunately, we never completely hit our stride together. We had some great moments, but we developed a real friendship and connection," he told the newspaper.
Taillon most recently pitched in the majors in 2019, when he went 2-3 with a 4.10 ERA in seven starts. He went 14-10 with a 3.20 ERA the previous season.
Taillon, who is under contract for $2.25 million in 2021, also missed time during the 2017 season while battling testicular cancer. His first Tommy John surgery was performed in 2014, when he was pitching in the Pirates' minor league system.
Yajure, a 22-year-old from Venezuela, made his big league debut last year and had a 1.29 ERA in three relief appearances. Cherington expects Yajure to compete for a starting berth in spring training.
The other prospects acquired Sunday by Pittsburgh are less advanced.
Contreras, a 21-year-old from the Dominican Republic, is 16-11 with a 3.25 ERA in three minor league seasons and was added to the Yankees' 40-man roster in November. He was rated the Yankees' No. 8 prospect by Baseball America after the 2019 season.
Escotto, 18, made his professional debut in 2019 and hit .315 with 11 doubles, 4 triples, 8 homers, 26 RBIs and 13 steals in 45 games for the Dominican Summer League Yankees.
Smith, a 21-year-old from Texas, has hit .280 with 50 doubles, four triples, 19 homers, 118 RBIs and 21 steals in three minor league seasons.
Yajure and Contreras are on the 40-man roster. To clear a roster spot, Pittsburgh designated outfielder Troy Stokes for assignment.
The Associated Press contributed to this report.