Hidalgo was traded from Houston to New York on Thursday for right-handed pitchers David Weathers and Jeremy Griffiths.
The 28-year-old Venezuelan has struggled this season, batting just .256 with four homers and 30 RBIs. He asked to be traded after losing his starting job to Jason Lane recently.
The Mets are hoping Hidalgo can provide some spark to an offense that entered Thursday ranked second-to-last in the National League in hitting (.248) and runs (265).
The Mets fired batting coach Denny Walling on Tuesday.
“We’re pleased to have him,” Mets manager Art Howe said. “I know what he can do. He’s a run-producer, an outstanding right fielder. He hasn’t played on a regular basis. He’ll get that opportunity here. It’s a fresh start for him. I know he’s a good middle-of-the-order hitter.”
Hidalgo hit .309 with 28 home runs and 88 RBIs last season, earning team MVP honors. He batted .278 with 134 homers and 465 RBIs in 813 games with Houston, where he started his big league career in 1997.
“We felt we needed someone to protect Mike (Piazza) and Cliff (Floyd), and he gives us that,” Howe said. “It’s definitely exciting, and I think our offense should improve. If our pitching stays fairly close to what it’s been, our prospects improve.”
Hidalgo hit .341 in April, but has struggled since, batting just .197 with no homers and eight RBIs.
The Mets will honor Piazza before Friday’s game in a special ceremony. Piazza passed Carlton Fisk for the top spot on the all-time homer run list for catchers with 355 earlier this season. Hall of Fame catchers Fisk, Yogi Berra, Johnny Bench and Gary Carter will participate in the ceremony.
Piazza, who has also been playing first base this season, caught Thursday for the first time since May 21 and will also be behind the plate Friday.
The Tigers split a day-night doubleheader with the Philadelphia Phillies on Thursday, giving them six wins in their last eight games.
Eric Munson homered and Rondell White and Ivan Rodriguez each doubled in the first game, a 6-2 loss, and Carlos Guillen hit a two-out RBI single in the 11th to give the Tigers a 5-4 win in the nightcap.