is insanely low. It's currently at three - yes, three hits per nine innings (six in 18). That's the lowest of any pitcher with at least 15 ip in the last 15 years.
Now obviously it won't stay that low (his BABIP is .132 and his MiL hit-rate is 6.1/9), but it does point to how great his 'stuff' is. His Batting Average Against is .103, also the lowest in baseball. BAA is an important stat for up-and-coming pitchers; it indicates a pitcher's stuff and an ability to prevent rallies/big innings, the easiest way for pitchers to lose a ballgame.
You can see how tough he is when opposing hitters have trouble squaring up the ball. That cutter has truly been a Cervelli-send for him.
However, he needs to cut down on his walks (5.5/9) to become a top-flight starter. As he throws more strikes his hit-rate will rise, his walk-rate will drop, and he'll throw more innings. That has to happen for him to take the next proverbial step. The question is: When will that happen?