The Minor League Coaches won't be making the decisions. They will take their order from higher up on how many innnings/pitches and what pitches are thrown by Chapman. He'll be treated like a racehorse.
You buy a new Racehorse from South America and no matter how great he was down there, you don't just pay the Kentucky Derby entry fee and make that his first race. You put him in a series of warmups and watch how he reacts in those races first.