Bellamy picked up a knee injury in the 1-0 defeat at former club West Ham on Sunday.
Hughes said: “Craig Bellamy and Robinho won’t be fit [to face Aston Villa].
“Craig got examined yesterday and he is having a scan today to allow the injury to settle down for 48 hours and those scans will be read.
“It is not an old injury. I saw it reported it was a reoccurrence of an injury he had before, it is not, it is a new injury.
“He has torn some fibres in his knee and obviously the extent of the injury will be shown in the scans.
“We just hope the best case scenario is probably two to three weeks.”
