"It's strange," Nieuwenhuis said. "I'm trying to keep it about baseball during the game, but right now, I've never been to this side of the stadium. It's pretty weird. It's hard to describe.
"I had a great time here, but I have to turn the page and have fun with this club."
Before Milwaukee took the field for batting practice, though, Nieuwenhuis was given the opportunity to reflect on his Mets career one final time as he and fellow teammate Carlos Torres received their 2015 National League championship rings.
"It'd be different if it were a World Series ring," Nieuwenhuis said. "I think it'll kind of close the book on that, but it will be really cool."
In May, Nieuwenhuis was hitting .311 with a home run and seven RBIs to emerge as a regular starter for Milwaukee.
"He's been really consistent," Brewers manager Craig Counsell said. "He's been a regular presence against right-handed pitching certainly, but he's done a good job and that is what has made him a regular."
As a rookie in 2012, Nieuwenhuis recorded 314 plate appearances for the Mets, but since then he has not received consistent at-bats. Last season, with two stints in New York and one with the Angels, he tallied 141 plate appearances, the second-highest total of his career.
Through 37 games with the Brewers, he has already made 21 starts, which is six away from his second-highest start total set in 2015.
"Some of the experiences here [in New York] that I had have taught me a lot," Nieuwenhuis said. "I try not to take anything for granted. Since I've been here [in Milwaukee] it's been great.
"This is a great locker room to be in and it's been a lot of fun."
Troy Provost-Heron is a reporter for MLB.com based in New York.