Midfielder Pedri lamented stupid makes and slowness on the ball as Barcelona's perfect start to the LaLiga season was ended by Real Madrid in the Clásico at Spotify Camp Nou on Sunday.
Kylian Mbappé scored twice either side of Raphinha's equaliser in the 2-1 win for Jose Mourinho's side, including an 87th-minute goal, as Madrid halted Barça's winning streak in the league at nine games to move within three points of Hansi Flick's team at the top of the table.
"In general, we didn't play well," Pedri told DAZN. "We were not ourselves in the first half. There are a lot of things we could have done better.
"We got back on level terms in the second half, but we did not defend the second goal well -- from a transition, as well, which we knew they could do.
"But, above all, in the first half we were really slow, we lost the ball stupidly a lot and you pay for those mistakes."
Mbappé gave Madrid a first-half lead when he turned home from close range after a poor clearance from Gerard Martín, but Barça fought back after the break through Raphinha's 15th goal of the campaign.
However, with Barça pushing for a winner late on, they left space in behind which Madrid took advantage of, breaking through with Eduardo Camavinga, who teed up Mbappé for his second of the evening and his 100th goal for Los Blancos.
It completed a miserable week for Barça. After 11 consecutive victories in all competitions, they have now lost back-to-back games after also losing 4-2 at Paris Saint-Germain last Tuesday in the Champions League.
Flick refused to label the defeats a "reality check," instead saying tiredness was the reason for the losses.
"It's two defeats so of course we are not happy; we are disappointed," Flick said in the post-game news conference. "The first half was not good. The second half, after the equaliser, was better. I think also we controlled the game. We missed a little bit of luck. But they played well, they didn't give us much space.
"Also, you could see today we missed the freshness. It's about this. It's the first defeat in LaLiga. We won nine in a row [in the league]. But it happens, defeats are a part of the game."
Flick said the results against PSG and Madrid will "not create doubts" around his team, instead doubling down on the fatigue his players are suffering and a defensive injury list which includes Andreas Christensen, Jules Koundé and Eric García -- and now Xavi Espart, who was taken off in the first half of the Clásico.
"No, no [doubts], that is clear," he added. "Everyone knows the situation, that we don't play very good. But in the big games, small things are important. They decide the games.
"We played against an opponent that has huge quality. They were better against the ball than in the Clásico in previous years.
"Like I said, you saw today we missed the freshness. After these weeks, it was not easy for my players. We have to now focus again and recover well.
"Maybe the most important point is the injuries we have in defence, also Dani [Olmo]. We have to manage it. At the end, in the defence, we had not a lot of options."
Barça remain top of LaLiga, two points clear of Atlético and now just three ahead of Real Madrid. They return to action next Saturday when they host Alavés.
