From MLB dot com:
http://mlb.mlb.com/news/article.jsp?ymd=20130621&content_id=51342078&vkey=news_mlb&c_id=mlb
From reading the article above, the Tigers think that Valverde has an issue with his arm slot. They think that it is something he can work on and straighten out fairly quickly.
I’m very interested in see if Jose will take a Toledo assignment. I hope he does.
“God, I love baseball.” – Roy Hobbs | The Natural
Flashin' Leather 
I think his problems are a little more than simple mechanics, but if that is all it is then maybe he still has hope. Now maybe the next experiment to end will be Coke.
I agree, I’m not sure Valverde can be fixed. And, you are correct again, Coke has been terrible!!!! It looks like he might turn into a guy that is brought in to get one batter out. That might be all he’s good for.
I now believe in G-d.