Seymour was recalled from Triple-A Sacramento on Monday.
Seymour has experience working as a starter, but lately he has been working out of the Triple-A bullpen, logging a 3.94 ERA, 1.19 WHIP and 18 strikeouts in 16 innings over eight appearances. He could eventually work in high-leverage situations after Erik Miller and Caleb Kilian were dealt at the deadline.