Well, when a pitcher has shoulder problems, that results in a drop in velocity. But, he has struck out 75 in 73 innings, so it can't be bothering him too much. His control is fantastic, he has walked just 16 in 73 innings.
He has been a victim of extremely low run support. In all of these games he has not gotten the win.
7 ip 2 er against ATL
7 ip 1 er against NYM
7 ip 2 er against ATL
5 ip 3 er against Arizona
His only problem is hr's, he has given up 11 in 73 innings.
Another thing to mention is that his DIPs era is 3.51. He has been affected by bad defense and terrible luck, he's certainly doing his part.
