Jose Mourinho insisted Real Madrid will win trophies with him in charge but stressed his second spell at the Bernabeu remained a work in progress ahead of El Clasico in Barcelona.
The Portuguese has won 10 and lost two of his 12 matches in charge since returning in the summer but are already six points behind their arch-rivals in LaLiga.
Barcelona have a 100% record in the league and have scored 39 goals in just nine games, scoring four or more in six fixtures.
By contrast Madrid have scored 23 goals, although they have scored four or more four times in the league, but when Mourinho was asked whether the trip to the Nou Camp was a test of their ability to contend he said: "No. Madrid with Mourinho wins titles."
Mourinho said he did not think their respective Champions League results in midweek - Madrid beat RB Leipzig 4-1 at home while Barca lost 4-2 at Paris Saint-Germain - made much difference to Sunday's game.
"People who, a week ago, thought Barca could thrash us probably still think the same. I don't think the Paris match or the Leipzig match at the Bernabeu will change their idea or way of thinking," he added.
"To be honest, there are moments and matches where they deserve to be spoken of highly when they do very good things.
"In our case, the only thing I think is that if you see us as a finished product, finished products in football are very rare because they are never truly finished."
"Far from being a finished product, we are a product in progress. Comparing a team in this state with a team that has been together for two or three years doesn't seem fair to me."
Barcelona boss Hansi Flick is looking for his 100th win in charge, while he could also establish a new record for the best start to a LaLiga season - surpassing Real's former mark of nine successive wins in the 1968-69 season.
The German brushed off the defeat in Paris, saying: "El Clasico is different. It's the best game football has to offer, and everyone will be watching.
"I have a good feeling. The players have recovered and are ready for the game. The team is really looking forward to playing it."
