Ferrer would find a way to lose against Nadal, I'm sure. Especially in a big match. That's just his style. Nadal's got a long way to go to even start facing a Ferrer-type player late in a tournament, though. His level is that poor.
Nadal is pretty poor at the moment, this is true, but we can't deny the court conditions are pretty horrid. hard to read a lot when he obviously is not going to go for crazy shots or run as much as normal on this dirt because he's afraid to injure himself
I think the key to Nadal right now is
confidence - success
he just does not have the confidence in the movement
as soon as he really trusts the knees
his game will improve tenfold