I firmly believe Gio's problems were mental. You can almost draw an exact line from where he fell off vs. his struggles.
However, he wasn't elite before then but he was good enough to be valuable in this rotation. If true, he could be a good #3#4 starter. If the Sox can get him back to where he was then they have a solid #1 #2 starter.
The injury adds another monkey wrench into the equation. Today, more than ever guys come back fine from surgery, but surgery is still surgery and you just never know.
Even if we witness best case scenario with Giolito, could we count on him down the stretch when his innings are getting high?