I frankly don't feel that comfortable with Johnson doing anything which will get 2 days of dedicated film study. I don't see him being a successful Big League pitcher in the long term. I'd love to be wrong, but I don't see it. He has great control, but I'm afraid he just doesn't have enough stuff to stick in the long run. Right now he strikes out more than half the guys he Ks on high fastballs. High fastballs at 89 miles an hour. It's awfully hard to make a career out of that pitch. Chen gets a lot of guys on fairly slow high heat as well, but at least in his case he has the threat of much crisper breaking stuff than anything Johnson features.
I do think Miguel Gonzalez has a good shot to stick. I've liked him just about every time I've seen him (except the time he was sick). He has a really sharp curve, great fastball command, and a decent change.