Barcelona shelled out an initial £96million to sign Dembele from Borussia Dortmund last month.
The Spanish giants were desperate to make a big signing after losing Neymar to Paris Saint-Germain in a £200m deal.
Dembele made his debut for Barcelona off the bench in their 5-0 win over Espanyol on Saturday, marking it with an assist.
But he underwhelmed at the Nou Camp last night as Lionel Messi scored twice in their 3-0 Champions League humbling of Juventus.
And according to Spanish website Don Balon, the claim at Real Madrid is that Dembele does not suit Barcelona’s style.
Barca are famed for their tiki-taka approach to the game, with their 4-3-3 formation utilised all the way through their youth system.
But 20-year-old Dembele is a player whose game is based on speed, which ironically is more in tune with Real than Barca.
Don Balon say Real boss Zinedine Zidane is a big fan of the France international and nearly signed him in January for a deal reaching £63m.
But the move never materialised and Dembele ended up a Barcelona player, in a deal which could eventually total £136m.
And Real are apparently content to have missed out on the former Rennes man, with Perez believing Barcelona signing him is like ‘buying a greyhound and tying him up’.