The Red Sox transferred Bello from Triple-A Worcester to Double-A Portland on Monday.
Boston initially optioned Bello to Worcester when he was cut from big-league camp March 25, but he'll instead open the campaign in Portland. The 22-year-old righty spent the majority of the 2021 campaign at Portland, producing a 4.66 ERA and 1.42 WHIP across 63.2 innings in 15 starts with the affiliate.