The Rays designated Romero for assignment Tuesday, Tricia Whitaker of Bally Sports Sun reports.
Romero received the chance to make his MLB debut in April as a starter, but after lasting just 1.2 innings while issuing five walks in that outing, the 25-year-old has been trending downward ever since. He went on to make two additional relief appearances for the big club but has otherwise spent the season at Triple-A Durham, where he struggled in a starting role before ultimately moving to the bullpen. The 25-year-old right-hander owns a 3.51 ERA, 1.24 WHIP and 58:25 K:BB in 66.2 innings at Triple-A this season, and his status as a prospect of some repute could prompt another organization to put in a waiver claim for him now that he's off the Rays' 40-man roster.