The Mets also placed outfielder Starling Marte on the 10-day injured list with a right groin strain that has bothered him for most of the season.
Baty homered in his first at-bat in Atlanta last August but has struggled for most of his career so far. He batted .184 in 11 games last season and is hitting .216 with seven homers and 27 RBIs this season.
Baty, New York's first-round pick in 2019, has particularly struggled since the All-Star break. He is hitless in his last 19 at-bats and 9-for-69 (.130) with 24 strikeouts in 21 games since the break.
"Just a little timeout, kind of 'take a breath,'" Showalter said before the Mets faced the Cubs in their first home game since trading Justin Verlander, Tommy Pham and Mark Canha at the deadline. "Mental, emotional, just kind of let him work on some things without the day-to-day. I think, Brett we know it's in the best interest of his development."
Baty was not on the opening day roster but was called up two weeks into the season to supplant veteran Eduardo Escobar. He batted .343 in his first 11 games but has struggled ever since.
In the second year of a four-year, $78 million contract, Marte is hitting .248 with five homers, 28 RBIs and 24 stolen bases in 86 games. Last season, Marte hit .292 with 16 homers and 63 RBIs to go along with 18 stolen bases in 118 games but also broke his right index finger on Sept. 6 when he was hit by Pittsburgh's Mitch Keller.
Marte also missed nearly three weeks with migraines and went 0-for-8 in two games in Baltimore over the weekend. In April, he dealt with a neck issue sustained after stealing a base.
"Sometimes things get kind of lost in translation," Showalter said. "I just want to make sure he knows he can keep his trust about what he's feeling. I think we all know by the level we've seen him play at last year that he hasn't been able to do that consistently."
Marte underwent double groin surgery after last season and will meet with the Philadelphia-based doctor who performed that procedure.
Marte was an All-Star in 2016 with Pittsburgh and has a .287 career average with 147 homers, 593 RBIs and 338 steals in 12 seasons with the Pirates (2012-19), Arizona (2020), Miami (2021), Oakland (2021) and the Mets.
To replace Baty and Marte, the Mets called up infielder Jonathan Araúz from Syracuse and selected the contract of outfielder Abraham Almonte from there.
Araúz went 1-for-6 in two games last week with the Mets and has also appeared in the majors with Boston and Baltimore. Araúz is batting .244 with 14 homers and 49 games for Syracuse.
Almonte is a career .235 hitter with 24 homers and 118 RBI in 10 seasons for Seattle, San Diego, Cleveland, Kansas City, Arizona, Atlanta and Boston. He is hitting .244 with 13 homers and 31 RBIs in 41 games at three minor league levels this season.