The Pirates designated Santana for assignment Thursday, Colin Beazley of the Pittsburgh Post-Gazette reports.
The move frees a spot on the 26-man and 40-man rosters for the addition of Ron Marinaccio. Santana began 2026 high in the Pirates' bullpen hierarchy, but he has struggled with consistency all season and had allowed 10 runs in 7.1 innings this month. It's possible he'll draw interest via waivers, though his $3.5 million salary could be a deterrent for some clubs.