Bubic (elbow) will have his rehab assignment transferred to Double-A Northwest Arkansas.
Bubic began his rehab assignment at the Royals' rookie level Arizona Complex affiliate May 7, and he'll now advance to Double-A. He made three appearances at the rookie level, allowing one run on four hits and two walks while striking out eight batters over 3.1 innings. The left-hander has been on the 60-day injured list since February as he has continued to recover from the Tommy John surgery he underwent last April.