So why get dirty if you cannot beat Nadal anyway?
He means Fed (or anyone) needs to change his tactics to 'dirty' tactics in order to have a chance.
Nadal is hypocritical in that he makes his living moonballing to people's backhands, yet his own backhand doesn't handle the high ball particularly well.
Someone needs to give the pig a taste of his own medicine and abuse his backhand - hit every serve kicking up to it, every forehand moonballed to it, every backhand looped back down the line to it, every volley goes back to his backhand...etc...
I would pay good money to see someone abuse Nadal like that.
However no-one will. we might as well not play the tournament - hand the title to Nadal - he will not lose a set (he probably won't lose a point).