The Red Sox designated Campbell (elbow) for assignment Tuesday, Jen McCaffrey of The Athletic reports.
Campbell missed the second half of 2024 with elbow inflammation and never got surgery, so the injury may have played a role in him losing his spot on the 40-man roster as Boston looked to protect some prospects from the Rule 5 draft. Campbell had a 2.20 ERA, 1.16 WHIP and a 19:5 K:BB in 14 appearances at Triple-A, but he gave up 12 earned runs in 6.2 MLB innings and his fastball velocity was down to 93.8 mph from the 95.0 mph he averaged in 2023 with Seattle.