BOSTON — The Boston Red Sox made a significant roster move Monday, acquiring left-handed reliever Erik Miller and outfield prospect Carlos Gutierrez from the San Francisco Giants in exchange for infielder Marcelo Mayer, the club’s former first-round pick and one of its most highly regarded young players.
The trade delivers Boston a dominant late‑inning arm in Miller and a fast‑rising outfield prospect, while San Francisco adds a young infielder with long-term upside.
Miller Brings Elite Swing-and-Miss Stuff and Ground-Ball Efficiency
Miller, 28, has been one of the most effective left-handed relievers in the National League this season. Across 38 appearances, he owns a 2.76 ERA, 10 holds, four saves, and 45 strikeouts in 32.2 innings. His underlying metrics place him among the league’s most dominant arms.
According to Statcast, Miller ranks:
- 99th percentile in average exit velocity (83.1 mph)
- 98th percentile in expected batting average (.181)
- 98th percentile in hard-hit rate (27.4%)
- 97th percentile in whiff rate (34.8%)
- 95th percentile in strikeout rate (31.7%)
- 92nd percentile in ground-ball rate (53.4%)
He has not allowed a run in 14 consecutive appearances dating back to June 19, posting a 0.85 WHIP and holding opponents to a .143 average over that span.
Originally drafted by Philadelphia in the fourth round in 2019, Miller has compiled a 3.05 ERA, 154 strikeouts, and a .210 opponents’ average across 147 career major league games. He has been particularly tough on left-handed hitters, limiting them to a .189 average and .550 OPS.
Gutierrez Adds Speed, Contact Ability, and Defensive Versatility
Gutierrez, 21, ranked No. 24 in the Giants’ system by Baseball America, has been one of High‑A Eugene’s most productive players this season. The left-handed hitter owns a .271/.826 OPS line with 18 doubles, nine home runs, 45 RBI, and 26 stolen bases across 83 games.
Signed as an international free agent in 2023, Gutierrez has hit .314 with an .866 OPS, 64 steals, and 85 RBI across 168 career minor league games. He has made starts at all three outfield positions, with the majority coming in left field.
Mayer Heads to Giants After Two Seasons in Boston
Mayer, 23, appeared in 70 games for the Red Sox this season, hitting .220 with 10 doubles, three home runs, and 22 RBI while splitting time between second base and shortstop. He was placed on the injured list June 26 with a bone stress reaction in his left ulna.
Selected fourth overall in the 2021 draft, Mayer has played 114 major league games, all with Boston, posting a .223 career average.
The trade marks a notable shift for Boston, which adds a high‑impact bullpen arm and a promising outfield prospect while parting with one of its most recognizable young infielders. San Francisco, meanwhile, secures a former top draft pick with long-term upside as it continues to build its infield core.
