Since Giroud has come back Sanchez has dropped the deepest out of Giroud, Welbeck and Cazorla. Like others have said, this might be the game Sanchez gets a rest.
I'd bench Downing over Austin. Would fancy QPR to score against a shaky Arsenal defence (and if they do Austin will certainly be involved), whereas Chelsea are likely to keep a clean sheet.
Just FYI to everyone thinking of a Manchester United player, we're going to play 352 again and we've really struggled with that formation.
Really hope Sigurdsson starts tomorrow as well. If not, he's out for Downing.