General manager Brian Cashman said Tuesday there was not a single instance that led to the decision.
"Maybe through a lot of therapy I forgot and eliminated it, but ultimately once he moved over to second, it was almost a relief for him," Cashman said. "So I'm sure there was a buildup over the course of a week or a 10-day period that a few things happened and it was like we have to do something here.
"And that came from the manager's chair, and he did it. He just told me, 'This is what I think we've got to do, and we're going to do it,' and I said, 'No problem.'"
Torres, who turns 25 next month, was primarily a second baseman during his first two seasons with the Yankees in 2018 and 2019. He filled in at shortstop when Didi Gregorius got hurt and was moved there for 2020 after Gregorius left as a free agent.
Torres made 18 errors at shortstop, third in the AL behind 24 by Toronto's Bo Bichette and 19 by Texas' Isiah Kiner-Falefa. Torres was moved to second base on Sept. 13 with three weeks left in the regular season.
Torres hit .259 with nine homers and 51 RBIs, up from .243 with three homers and 16 RBIs during the pandemic-shortened 2020 season but down from .278 with 38 homers and 90 RBIs in 2019, when he made the AL All-Star team for the second straight season.
Cashman is in the market for a shortstop.
"Once we signed [DJ] LeMahieu back, we knew that it was going to cement Gleyber as our shortstop, and so we had hopes that it was going to work out, but it didn't," Cashman said.
Cashman praised ace Gerrit Cole, a finalist for the AL Cy Young Award, after going 16-8 with a 3.23 ERA despite second-half struggles.
Cole began 8-3 with a 2.31 ERA in 14 starts. Then, after Major League Baseball launched its crackdown on unauthorized grip substances on June 21, Cole went 8-5 with a 4.12 ERA in 16 starts.
"He was fantastic for us this year," Cashman said, "despite obviously injuries" and "some changes in the game."
Cole was 1-1 with a 7.64 ERA in his last three starts after returning from left hamstring tightness and lost the AL wild-card game against Boston, allowing two homers and three runs while lasting two innings.
"He's never going to say the hamstring bothered him, once he kept going again. He's never going to say he was tired," Cashman said. "But I think all of that's possible."
Cashman said the Yankees will have contract talks with the agent for Aaron Judge, who is eligible for free agency after next season. Judge is eligible for salary arbitration after making $10,175,000, and New York could try to negotiate a multiyear deal.
Outfielder Clint Frazier did not play after June 30 because of what the Yankees have listed as vertigo. Cashman said Frazier is working out in Atlanta ahead of 2022.
"There's a lot of expectation and optimism that what transpired will not be an issue as he enters next season," Cashman said.
Cashman wouldn't detail any new information on Frazier's diagnosis, saying "he can speak to it at some point whenever he's comfortable doing so."
Frazier missed a large portion of 2018 with a concussion after he collided with an outfield wall during a spring training game at Bradenton, Florida.
"I'd love to have the opportunity to talk about this situation publicly and probably plan to do so soon," Frazier wrote on Twitter on Oct. 11. "My issues have been very personal to me and something I've wanted to handle privately, but there's been a lot of inaccurate things reported about my injury that I'll clear up."