Andy has played DC within the last two years. Last year after the USO, just prior to the surgery.
As for Djokovic, I smell a hissy fit over Troicki. If he's tired, fine, but isn't it funny that he doesn't complain about being tired any other time? Personally I think Novak's knickers are still in a knot. Good, he's funny when he gets annoyed about something.
Federer's so obvious you just have to laugh.
I disagree about the "hissy fit" comment; Djoko's been a DC stalwart for years, winning the title in 2010, going to the finals again last year. In fact last year he won more DC matches than any other player on tour even though they didn't win the final. To look for underhanded reasons he has decided not to play seems unfair in his case. Maybe he's being realistic though: Troicki is banned, Tipsarevic is injured, Zimonjic is ageing (he's 37), so is Nole supposed to carry the whole team? They have a couple others but the team is really depleted at the moment. It's not that much different that the GB team, arguably. Serbs, Brits don't have the depth of the Spanish or French. I think you need at least 2 healthy and strong players and/or 1 with a strong doubles team to have a shot at the title. Hence, the Swiss have a shot this year I guess.
As for Djokovic not playing the doubles match in last year's final, that was the decision by his coach because they needed him to win both singles matches and because Zim and Bog had been successful in doubles throughout the year, so why change it if it aint broke? But Djoko was also held by the ITF guys for 4-5 hours the day of the doubles match.