Flynn (back) was reinstated from the 60-day disabled list and optioned to Triple-A Omaha on Monday, Rustin Dodd of The Kansas City Star reports.
The left-hander injured his back prior to the start of spring training, and he'll have to earn his way back onto the 25-man roster. Should he secure a promotion, Flynn could provide some help for a Kansas City bullpen that ranks 12th in the AL with a 4.51 ERA. The 27-year-old posted a 2.60 ERA and 1.10 WHIP with 44 strikeouts across 55.1 innings out of the Royals' bullpen last season .