If Ferrer makes the semis of the big tournaments (USO, Shanghai and Paris), he'll get around 1400 points I think. Then there is Tokyo/Beijing and Valencia 500, Bangkok 250 (and some others, can't remember). So it's going to be difficult but not impossible.
Then of course if Nadal doesn't play WTF and Ferrer makes the semis there as well, he'll get even more points.
He'll be more than 2000 behind IF he makes USO SF which is not a given. Then best case scenario IMO:
Malaysia 250 - W
Beijing 500 - F (300) - Djokovic and Tsonga are also playing here so getting to final won't be easy at all....
Shanghai 1000 - SF (360) - Federer, Murray, Djokovic - getting to the final too much IMO
Valencia 500 - W (500)
Paris 1000 - SF (360)
To me this is not easy at all for Ferrer. If he does this he has 1770 points. Would need then a couple of wins at the WTF (probably with a full strength Djokovic and Murray unlike last year) to get to the 2000 point mark... Of course theoretically Ferrer could do it but think it's a massive task. And it may be that Nadal decides to play WTF anyway.