Now, the Royals have rewarded Zimmer for the turnaround. The club promoted him to Double-A Northwest Arkansas on Friday. Zimmer is scheduled to make his debut with the Naturals on Saturday.
Zimmer was the fifth overall selection in the 2012 First-Year Player Draft and is ranked No. 28 on MLB.com's Top 100 prospect list. His upper-90s fastball is his best pitch, but his changeup, curveball and slider all have the potential to be above-average Major League offerings.
Even when Zimmer was struggling at Wilmington this season, hitters still had trouble making contact against him. He struck out 113 batters in 89 2/3 innings in 18 starts for the Blue Rocks and leaves the Carolina League as its strikeouts leader.
Dick Kaegel is a reporter for MLB.com. Teddy Cahill is a reporter for MLB.com. Follow him on Twitter at @tedcahill. Kathleen Gier is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.