Not every pitcher is a strikeout pitcher, in fact most aren't. Judging anyone based on one metric, is always hazardous. He's 23, and was the consensus top high school pitcher in 2013, and not unlike Mauer, practically a world class athlete. I'm in no big hurry, let's see what the fat lady does.
You don't have to be a strikeout pitcher (lets say 8+ K/9) but you can't be at the absolute bottom (basically avoiding strikeouts).
Among pitchers with 500IP from 2013-2017 there are only 6 MLB pitchers (Guthrie - Buehrle - Martin Perez - Kendrick - Simon - Pelfrey) with a <6 K/9. You can have success with out strikeouts but his MiLB numbers rate as among the worst in the majors. Perhaps he can be Buehrle but he is almost the exception.