Did you know that something called "development" occurs with prospects? Fact of the matter is, as @sveumrulespoints out, he's walked 5 over his last 6 starts while striking out 40 (8.0 K/BB) over 36.1 IP with a 3.22 ERA. He's not the same pitcher he was earlier in the year, when the Brewers signed Teheran, who is literally the only pitcher you can say they signed off the street and brought directly to the major leagues.