Federer thinks that Nadal has a mental block against Djokovic since the latter has beaten the former the last five or six times they have played each other.
That is amusing given that Nadal still has a better head-to-head against Djokovic who is in the midst of possibly the greatest purple patch of them all.
Meanwhile, Federer has a mental block of his own. Against Nadal. 8-17 in career matches.
Must have slipped his mind.