I've no idea, but remember that they have to fit women's matches in as well.
Well I haven't been able to watch any of his matches here, or Delpo's either, but I've a feeling that Delpo will have the edge if only on the level that Andy has played just three matches - all of them against players he should beat (although the grunting Berlocq seems to have been a bit of a handful) - since the AO. Delpo on the other hand has had a tougher draw and also has the benefit of having played, and won, Rotterdam, so his confidence will be high. Mind you, as Berlocq is also Argentinian, Andy might just be wanting revenge for what he claimed was gamesmanship.
I think Aileen because you haven't seen how each of Andy's opponents have come out playing lights out tennis, firing from both barrels because they had nothing to lose. Also Andy was playing a man he had never played before or only once, they on the other hand would have watched many of Andy's matches. Del Po was match fit and played against men he's played against before on a surface that has aided him. One of the reasons I think Andy has shown a Champions mentality and grit by winning through to the quarter finals. I think as his match is the second match will help Andy and he will try and move Delpo around, as he has in the past and raise his game and win through. Delighted to see 'poor old injured Fed' beaten. He was not a happy man as he has 2 players who have his measure as we see from the H2H's (Andy and Rafa) and either or one or the other will be in his side of the draw.