Giants Acquire Marcelo Mayer in Return For Erik Miller5 of 10Jaiden Tripi/Getty ImagesMarcelo Mayer has hit .223 with a .625 OPS in 114 games. But he's a former first-round pick who is still only 23 years old and was one of the top 10 prospects in baseball ahead of the 2025 season. It just felt a little early for the Red Sox to give up on him. It would be one thing if the Red Sox moved him for a superstar. Erik Miller is a nice left-handed reliever, as evidenced by his 2.76 ERA over 38 games this year.