Allardyce tried to sign the striker for just £3m in 2010 when he was at Blackburn. However, he failed to convince the Ewood Park board to stump up the cash.
Allardyce said: "I think about it every time I see him play. I think the board said we are not going to commit that amount of money. It was three or four million Euros. There were a lot of people looking at him at that time but we had the edge over everyone else because of the attraction of the Premier League. It didn't happen and it will be about £40m after Wednesday night."