He needs to get his head checked. He is so damn erratic, and it's painful considering he has so much potential.
I think he'll improve mentally next year. To say this is his first full year playing only ATP events he's done really well. The game is there, he just needs more focus which should hopefully come with time.
This year he's gained experience of playing against the top guys (and has pushed them) which should help him when they meet again. Ferrer said afterwards that he thinks Jerzy can be a top 10 player - he's definitely got the potential to get there.