Marcelo Mayer, San Francisco Giants3 of 5Paul Rutherford/Getty ImagesEntering the 2025 season, Marcelo Mayer was ranked by MLB Pipeline as the No. 12 prospect in baseball, with the following scouting report:"Bigger than most shortstops, Mayer has below-average speed but his quick first step and instincts help him compensate. Some evaluators like him better at third base, where they believe he could be a plus defender with profile power." Granted, Mayer has since hit just .223 with a .625 OPS across his first 114 MLB games. Still, the idea of trading Mayer for Miller a year ago would have been comical.