Bello is starting Sunday's game against the Blue Jays, Jen McCaffrey of The Athletic reports.
Manager Alex Cora indicated Friday that there was a "good chance" that Bello would start Sunday's series finale against Toronto, and the right-hander will officially make his third major-league start. The right-hander has posted a 10.13 ERA and 2.38 WHIP in eight innings over two starts for the Red Sox this year.