Yesterday Mourinho, who had previously publicly stated that Robben was certain to stay at Stamford Bridge, admitted that was not the case.
"I cannot speak about it," he said when asked about the 23-year-old's future.
"Until the 31 August [when the transfer window closes] everything is possible in terms of people to come and people to go. I think the situation has a lot of speculation behind but of course also some truth. And we have to wait a bit more to see."