Valdes fluffed his first touch and allowed Real winger Angel Di Maria to fire home but Mascherano said Barca would not be abandoning their insistence on always playing the ball, in which Valdes had an important role.
"It was a passage of play that only the Barca keeper can do and this style is why Barca is so recognisable," Mascherano told reporters ahead of their La Liga match at Osasuna on Sunday. "We prefer to make the odd error so we can continue to be ourselves."
Barca's France fullback Eric Abidal has begun light training in the gym for the first time since a liver transplant in April, the 32-year-old said on Thursday.
"I've started again to train indoors, for a little time now," Abidal, who has targeted a return to action in December, wrote on his Facebook page.
Real's Brazilian playmaker Kaka looks even closer to leaving the champions after coach Jose Mourinho left him out of the squad for the Super Cup match.
"Kaka was not part of my plans," Mourinho said bluntly after the match.
Real, who play at city rivals Getafe on Sunday, paid around 65 million Euros to buy Kaka from AC Milan and he has been linked with a move back to the Serie A club or to big-spending French side Paris Saint Germain.
Real will likely be missing Pepe again for the match across town at Getafe after the Portuguese defender suffered a head injury in last weekend's 1-1 home draw with Valencia.
"Nobody doubts the importance of Pepe for this team but we have a very big squad," fellow centre back Sergio Ramos told reporters after the Super Cup game.
Spain defender Raul Albiol was more than capable of filling in until Pepe returned, Ramos added.
Valencia fans will have a chance to welcome new signing Aly Cissokho at a special event at their Mestalla stadium on Friday night after the club lured the France defender from Olympique Lyon.
The 24-year-old has agreed a four-year contract and Spanish media said the deal was worth around six million euros.
Valencia, who finished a distant third in La Liga last season behind champions Real and Barca, host promoted Deportivo Coruna on Sunday
Malaga coach Manuel Pellegrini has hit out at the professional league (LFP) for setting some match kick-off times at 11 p.m. in the evening local time, including the Andalusian club's game at home to Real Mallorca on Saturday.
"It's not a normal time to play a football match," said Pellegrini.
"People need to get home afterwards and maybe for a lot of people that will stop them coming to the stadium," added the Chilean. The LFP has said one reason for late kickoffs is to avoid the summer heat.club.