However, Robson has insisted that it isn't as big a deal as certain sections of the media are making out.
"It just so happens that we played on the same day," she told a press conference.
"Obviously everyone tried their best but Heather played Victoria Azarenka, who is in great form, so that was a tough draw and Anne had a virus.
"I am not trying to make excuses for us but I don't think it's a disaster."
Andy Murray is now the only Brit remaining in the competition.