Keane says the Spurs chief is 'more ambitious now than ever' to bring success to the club.
"Let's be real here guys, Daniel Levy has done unbelievable things for Tottenham - the stadium and the training ground - and he deserves a lot, a lot of credit for that," he told beIN SPORTS.
"There were a lot of people saying there was going to be a banner flying today, which is crazy, because what he has done for that club is incredible and he'll support Mourinho again next year – he will give him funds to build this team. He is more ambitious – and I know Daniel very, very well personally – he is more ambitious now than he ever was because he wants success for Tottenham Hotspur.
"He's done the stadium, an incredible stadium as we all know, the training ground is probably the best I've seen in Europe: now you just have to deliver silverware. And giving Jose the funds which I presume that he will next season, I'm telling you this could be big from Tottenham next season."