Yakubu has to be starting the vast majority of our games. Saha is pretty much finished, and I'd rather see Beckford come on against tired defenders for the last 15-20 minutes.
The other thing to remember is that he plays on the shoulder of the last defender, and we don't really have a player who can provide those sort of through balls, along the deck, for him to run onto. Pienaar and Baines could do it, but I'm not sure anyone else would have the skill or awareness to do so (including Arteta). We could try lofted balls over the top too, but centre backs would be all over them anyway.
So yeah, Yakubu starting games and Beckford coming on late on.