The Marlins selected Zuber's contract from Triple-A Jacksonville on Monday.
The 30-year-old reliever made 10 appearances at the big-league level in 2025 between stops with the Marlins and Mets, but he had been pitching exclusively at the Triple-A level this season before receiving a promotion. Though Zuber posted an eye-popping 33.9 K% in 27.2 innings at Triple-A, he struggled to keep the ball in the yard (six home runs allowed) and walked 12.6 percent of the batters he faced. The Marlins have nonetheless opted to bring Zuber aboard as a fresh arm in relief after the team needed six pitchers plus position player Javier Sanoja to cover eight innings during an impromptu bullpen game in Sunday's 10-1 loss to the Mets.