The Pirates traded Fulmer to the Mariners on Tuesday, Francys Romero of BeisbolFR.com reports.
Fulmer has spent the entire season at Triple-A Indianapolis, posting a 6.35 ERA and 1.65 WHIP alongside a 27:15 K:BB across 34 innings. The 32-year-old's performance is unlikely to improve significantly now that he'll be moving into the Pacific Coast League, but he'll still provide some organizational bullpen depth at Triple-A Tacoma.