If everybody is healthy, this could be the best tie of the quarterfinals.
Although Argentina is obviously with the upperhand, since it's their home tie and their chosen surface, it's hard to overlook that a hot Safin can beat anybody, anywhere.
Indeed, this looks like it could come down to the doubles, which would be the most exciting senario. I suspect that David-Lucas are the planned pair, or they would not continue to be playing doubles in tournaments, soley with each other. Especially seeing as Lucas as dropped his former partner, Etis (sp?), in order to play with David.
As for singles, I have to think that Gaudio is a given, but the other slot is slightly wide open I think. I believe that they will play somebody else (Coria, perhaps?) on day one, and then maybe play David day three, depending on how many times he gets bagelled by Zabaleta over the next month, that is
Unless of course, they could just pick Chela, which might be the more likely senario. But you have to look fondly on the week that Mariano is having, and wonder what they will do if he keeps playing like that.