No its US vs GB last time I checked.
I think everyone knows that it's the USA v Andy Murray without him they won't win not at this level. I just hope he doesn't feel pressured into doing it because the public have changed their perception of him. Whatever is said it is patently obvious that Andy just wants to be liked and he has had to spill blood and guts on a tennis court to finally have most of the nation behind him.
Hopefully he will only play the singles but remember the last doubles match and Colin Fleming saying looking across the court and seeing Andy Murray as his doubles partner made him raise his game.
I hope Andy gets out of it the good he usually does i.e. team spirit, being part of a team, being with people he trusts and representing his country and that he comes away from it without any further back problems.
So really it is the USA v Andy Murray and the USA knew that hence their choice of surface!!