Could be, Dani. Here's a shot from the Squash Back The Bid promo. Different over-shirt and colour of t-shirt, but anything is possible with photoshop.
And if it is a fake by PF.. well, that's even more hilarious, innit?
Oh,sorry,looks like I was totally wrong about which picture used then!Woops!
I know for sure PF has done it before,with other pictures very cleverly and neatly photoshopped,which I've always thought was brilliant.One particular one I remember was one in which he talked about his loss to Berdych at the USO,and he had photoshopped the press conference picture
Really enjoyed that one!
So yeah,my guess would be that the picture is another stroke of genius from PF.But like I said above,I could well be wrong,and if I am then I take my hat off to Fed.