The Sun report that the Cottagers' £3m bid for the midfielder, 27, was accepted by Aston Villa and Sidwell is keen to go to Craven Cottage.
But Villa chief Martin O'Neill admits he does not know whether the deal will still be on now new boss Hughes is in charge.
O'Neill said: "The manager who was expected to go there, Martin Jol, has stayed where he is. I don't know if a new manager will make things happen quicker or not."