Shoppach, acquired from the Boston Red Sox on Aug. 14, hit a two-run homer in Monday's 5-4 loss at St. Louis.
The eight-year veteran had spent his entire career in the American League prior to the trade.
Shoppach was batting .303 with three homers and nine RBIs in 11 games with the Mets entering Tuesday. New York has won five of the last six games in which he has appeared.
Shoppach says part of the key to his success in switching leagues comes from his lack of knowledge regarding NL hurlers.
"Sometimes, as a catcher, I can out-think myself," he said. "Not knowing anything about the pitchers simplifies what I'm trying to do."
Shoppach triggered a ninth-inning rally with a two-run single on Saturday in a 5-3 win at Miami.
"I just go in with a real simple game plan," he said.
Mets manager Terry Collins has been just as pleased with Shoppach's defensive work in helping the club's young pitching staff.
"Experience like his is very valuable," Collins said. "He's aware of what needs to be done in every situation."