Castillo struggled in his previous appearance, blowing the save, surrendering two earned runs over an inning. The shoulder injury could explain his recent struggles, and he will miss at least the next 10 days. Paul Sewald will handle closing duties for the Mariners while Castillo is sidelined. Sewald has been terrific in 2021, owning a 2.63 ERA, 0.90 WHIP, and 67 strikeouts over 41 innings. Fantasy managers in search of saves should add Sewald in all league formats.