stats don't tell everything, he's pitched around 8 in. (i think) and been solid for at least 6. That's not bad for a 23 y.o. His bad innings also weren't HUGE. 3 runs isn't a huge inning.
Yes diaz hasn't been impressive, but in no way has he been terrible. He's settled down after giving up his runs, things could be alot worse. I say give him at least one more start.......