Bello was recalled from Triple-A Worcester on Wednesday.
Bello will make his major-league debut as the starter during Wednesday's series finale against the Rays following a strong showing in the minors to begin the year. The right-hander is among Boston's top prospects and has posted a 2.33 ERA, 114:33 K:BB and 1.02 WHIP in 85 innings over 15 appearances (14 starts) between the Double-A and Triple-A clubs this season. Since several of Boston's starters are dealing with injuries, Bello should have a chance to draw additional starts if he performs well Wednesday.