Di Santo is on a half-season loan at Ewood Park and has so far made three appearances since linking up with Rovers.
He impressed during Saturday's 2-1 win over Aston Villa and Allardyce has been pleased with the young Argentinian's contribution to date.
However, the 20-year-old is unlikely to extend his loan at Blackburn as Chelsea's transfer ban is expected to see Di Santo return to Stamford Bridge in January.
Allardyce is keen to make the most of the forward's time in the North West and also believes his loan spell will be of benefit to Chelsea.
"Franco has contributed a huge amount," said Allardyce.
"He could have gone on loan to a club in Europe, but Chelsea wanted to find out whether he is good enough for the Premier League.
"There's no doubt that if he continues to play like he did on Saturday he will be great for us. Then perhaps Chelsea can benefit."
Arsenal 1/5, Draw 5/1, Blackburn 14/1