Pep Guardiola's side defend a 2-0 lead from the first leg when they host their arch rivals next week, but the Argentina international has warned that it's not over yet
A brace from Lionel Messi secured the win for Pep Guardiola's side, while Jose Mourinho's charges were reduced to 10 men with the dismissal of Pepe in the second half.
Mascherano is refusing to accept his side have secured a place in the Wembley final and is adamant Madrid will attack at the Camo Nou next week.
"I'm very content with the outcome from this match, but this doesn't change anything for the second leg. There is another game to be played and Real Madrid are a very strong team that will do their utmost to turn things around," Mascherano told AS.
"It will be a very difficult encounter at Camp Nou. Real Madrid are a great rival and won't give up after this match."
Mascherano refused to comment on the referee's decision to dismiss Real Madrid's Pepe after the break.
"I have nothing to say on the incident as I didn't see it very well. The important thing for me is that we were true to our philosophy. That makes me a happy and satisfied person."