Stilson was released by the Pirates on Monday, Rob Biertempfel of The Athletic Pittsburgh reports.
Stilson was the Blue Jays' Comeback Player of the Year in 2017 after posting a combined 3.19 ERA across 53.2 innings split between Triple-A Buffalo and Double-A New Hampshire. The 27-year-old will now look for a minor-league deal elsewhere as he attempts to make his way to the majors for the first time in his career.