The Mets and Blue Jays will play a two-game interleague series at the Rogers Centre, where Bautista starred for the better part of nine years.
The Mets will start right-hander Zack Wheeler (2-6, 4.47 ERA) against Blue Jays right-hander Marco Estrada (4-7, 4.53) in the series opener.
While the Blue Jays (39-45) were losing 3-2 in 10 innings on Monday afternoon to the Detroit Tigers at the Rogers Centre, the Mets (33-48) had the day off. It gave Bautista a chance to renew acquaintances in Toronto.
"I have some stuff scheduled, to meet up with people who were part of my life when I was there and visit some of the usual spots," Bautista told reporters in Miami, where the Mets played last weekend. "It's definitely a place that I hold dear and close to my heart. It's going to be a fun time."
Bautista twice led the American League in home runs with the Blue Jays, hitting 54 in 2010 and 43 in 2011. His most famous home run came in 2015 at the Rogers Centre, a three-run blast with an iconic bat flip that won the American League Division Series in the fifth and deciding game against the Texas Rangers.
He played 1,235 regular-season games for the Blue Jays from 2008 to 2017, hitting 288 homers (second only to Carlos Delgado's 336) with 776 RBIs (third on the team's career list).
Bautista also had an influence on his teammates.
"He was a huge help in my development," Blue Jays center fielder Kevin Pillar said. "There was a time in my first full year when I went from left to center and I was making some plays and I kind of earned his respect and he metaphorically gave me the keys (to the outfield) and told me to go get anything I could. And my voice became the voice in the outfield. That was pretty special to me."
When the Blue Jays did not pick up the option on his contract for this season, he became a free agent. He did not have a team until the Atlanta Braves signed him on April 18. After a minor-league stint, he struggled with the Braves for 12 games and was released May 20. The Mets signed him May 22.
In 36 games with the Mets, the 37-year-old is batting .250/.418/476 with three homers and 13 RBIs. In his past 14 games, he is hitting .300/.462/.650 with three homers and 10 RBIs.
"I'm not surprised by what he's doing," Mets manager Mickey Callaway said. "He probably just needed some at-bats to get going and now we're seeing the byproduct of him being ready. I've always known he's a really good hitter. He keeps himself in really good shape. He's probably in the best shape of anybody on our team and is (the oldest player on the team). Great approach, great patience, still has bat speed."
"Not having a spring training, wanting to swing the bat and some other things might've played into me not (reaching base) as much in Atlanta," Bautista said.
Bautista always has been a versatile player. He played mostly right field with the Blue Jays but also manned third base and occasionally first base. He has played 12 games in left field for the Mets, 10 in right field, two at third base and one at second base.
This will be the second series between the teams. They split two games on May 15-16 at Citi Field.
Wheeler was the losing pitcher on May 16, a 12-1 Blue Jays victory, in his only career outing against Toronto. He allowed six runs, seven hits and three walks and struck out seven in four innings.
Estrada is 0-2 with a 7.27 ERA in seven career games (two starts) against the Mets. He struggled earlier in the season but is 2-1 with a 2.35 ERA in his past five starts.