Di Santo, who has impressed for Blackburn since joining, is on loan at the club until January.
But Allardyce has several times hinted that he would be keen on extending the striker’s stay at the club.
Allardyce said: “I do not think that there is any real chance of that.
“There is a transfer ban on Chelsea and with the African Nations coming up they will probably need him.
“Di Santo was terrific – he is a young man learning his trade. He has finally got a chance to start some games and he has grasped it.
“What pleased me was the lay-off for Dunny’s goal. He will take confidence as well from his first goal in the Premier League. If he can continue to play like this it will be good for us and Chelsea.”
