New York called up Smith and put right-hander Seth Lugo on the paternity list Monday before their 6-0 victory over the Miami Marlins. The move comes as Major League Baseball began enforcing a rule limiting teams to 13 pitchers that has been delayed several times.
Smith was optioned to Syracuse on May 31 after hitting .186 without a home run in 101 plate appearances this season. He hit .316 during a breakout season in 2020, but he hasn't been the same player in the majors since.
The 2013 first-round pick batted .266 with two homers and a .785 OPS in 15 games at Triple-A.
"He went down and did what he was asked to do," Mets manager Buck Showalter said after Monday's game, adding: "We wanted to get him going because we knew he was capable of better."
Mets left-hander David Peterson is expected to join Lugo on the paternity list soon. Peterson started Monday's game against Miami, but New York had contingency plans in place in case his wife, Alex, went into labor.
Mets manager Buck Showalter joked Monday morning that New York was on "baby watch'' with Peterson, Jeff McNeil and Seth Lugo all awaiting newborns.
Peterson was prepared to leave the park if Alex went into labor with the couple's first child, and the Mets had contingencies if he couldn't make the start. Peterson had his phone stashed in the trainer's room, hoping someone would hear if it rang, but he was reasonably confident he had time to pitch before his son arrived.
"Once I'm here, it's all about the game,'' he said. "If it rings, it rings.''
After being inconsistent with his mechanics this season, Peterson (4-1) was on top of his delivery and covered 5 innings with a season-high seven strikeouts on 100 pitches. He allowed six hits and two walks as the Mets won the four-game series by finishing their 11th shutout this season, tying the Yankees for the major league lead.
The Associated Press contributed to this report.