Boston Red Sox right-handed pitcher Brayan Bello is set to return from the injured list to start against the Seattle Mariners, following a right shoulder strain. To accommodate his return, reliever Zack Kelly will be optioned to Triple-A Worcester. Kelly struggled in his recent outing, allowing multiple runs and finishing with a high ERA. Meanwhile, manager Alex Cora expressed optimism about Bello's performance, noting his improved velocity and pitch action from rehab appearances.

Bello, who missed spring training and started the season on the IL, aims to build on last year's experience, focusing on execution and confidence. Cora hopes to get a solid five innings from him, emphasizing the need for Bello to trust his capabilities as he returns to the mound.