The Rays designated Whitley for assignment Saturday, Ryan Bass of FanDuel Sports Network Sun reports.
After being dealt to Tampa Bay from Houston on June 13, Whitley got into five big-league games and allowed 10 runs (eight earned) while posting a 4:2 K:BB over 4.2 innings. All of the runs against him came over his last two outings, one of which was a six-run blow-up against Detroit during which he didn't retire a batter. Whitley's removal from the roster made room for Tampa Bay to call up lefty reliever Joe Rock from Triple-A Durham.