While it wasn't exactly the debut that Joe Mack was hoping for, the Miami Marlins' No. 4 prospect is officially a big leaguer. Slotting into the No. 7 spot in the lineup and catching a strong outing from Janson Junk, Mack went 0-for-3 with a strikeout in a 1-0 loss to the Philadelphia Phillies. The game was the first of the 23-year-old's MLB career after the Marlins opted to call him up while demoting Agustín Ramírez to Triple-A Jacksonville. Mack stands as a key component of Miami's future, and now a part of their present. As baseball's 54th-ranked prospect, there has been considerable buzz surrounding the Williamsville, NY native after hitting 21 home runs and sporting a .813 OPS across two minor league stops in 2025 and then producing a standout spring with the Marlins. And Mack may not be the only new face to make their way to Miami this season. The club's ever-evolving roster could be in line for further injections of youth, with other MLB-ready prospects inching closer to their own debuts.…