There's potential there for sure.
His problem will often come against patient clay court specialists. Although he's improved his fitness considerably, I still wouldn't fancy him in a 3 hour battle with guys like Canas. He also doesn't have enough patience to go deep in a rally, though I believe Corretja is trying to improve that.
His game is ok for clay though, he used the angles well, is one of the best on tour at constructing points, and his movement is good enough.
He actually used to describe it as his favourite surface, he had a lot of success in the lower levels.
Adee-gee always has the best posts