Sanchez, 27, struck out four times in the Yankees' 6-1 loss to the Baltimore Orioles on Saturday night and is currently in a 5-for-40 slide, hitting .130 with only 21 games left in the regular season. Erik Kratz was in the lineup Sunday and went 0-4 while batting eighth and catching Masahiro Tanaka, who took the loss in Sunday's 5-1 defeat to the Orioles.
"Deliberated on it a lot last night. I just feel like this is the way I need to go right now with and hopefully a day off or two, or however I decide to do it here, can help get him going," Boone said in a video conference Sunday afternoon. "It's on all of us to get around him and try and help him get to what we know he can be."
Boone said the move was not an indictment on the catcher's work ethic.
"Gary wants to play, and to his credit, behind the scenes he's working his tail off and wants to be in there," Boone said. "But in the end, I think this is the best thing right now."
Sanchez, who has 48 strikeouts over 32 games this season, was once among the most dangerous hitters in the game but is slashing .130/.237/.350 with one double, seven home runs and 15 RBIs this season. Last year, Sanchez hit 34 home runs and 77 RBIs in 106 games.
His 48 strikeouts are the third-most through a player's first 32 games of a season in Yankees history, behind only Tyler Austin (52 in 2018) and Giancarlo Stanton (51 in 2018), according to ESPN Stats & Information.
"When you've had the kind of success that Gary's had at the big league level, you want to just find that good feeling of 'OK, I know when I'm right, I'm a beast. I'm a problem for teams,'" Boone said. "There are some subtle adjustments that can be made that hopefully can unlock him, and he's got to find that inside."
Outfielder Aaron Hicks, who is hitting .185 in his past 10 games, was also out of the lineup in an effort to give him a mental break. Rookie Estevan Florial was called up after pitcher Miguel Yajure was returned to the club's alternate training site.
"I hope our clubhouse always understands that ultimately the team and our success as a team comes first," Boone said. "We care about who they are and their careers. You're constantly trying to strike that balance. Along the way comes difficult decisions, decisions that players are certainly going to disagree with, and that's OK."