Bello will be added to the Red Sox's 40-man roster Friday, Alex Speier of The Boston Globe reports.
One of Boston's premier pitching prospects, Bello can touch triple digits with his fastball and sports a strong changeup and useful slider. He pitched better in 15 starts at Double-A than his 4.66 ERA indicates (3.12 FIP) and struck out 87 in 63.2 innings. If Bello handles Triple-A, he could debut in the majors next summer.