Real Madrid goalkeeper Keylor Navas said the club's players "are really hurting" after Saturday's humiliation at the hands of Barcelona.
Madrid, who have lost their last two La Liga games, were thrashed 4-0 by their arch rivals in the Bernabeu Clasico.
Speaking after the game, midfielder Luka Modric said Real "did not play as a team," while angry home fans vented their frustration by whistling star attacker Cristiano Ronaldo during the second half.
Costa Rica international Navas said Real, who face Shakhtar Donetsk in the Champions League on Wednesday, needed to pull together as a team.
He told the club's official website: "We all have to run that bit harder. We're a team, and it isn't a question of some of us running more or less.
"I have confidence in all of my teammates. I know the qualities that they have and the type of team that we are. We're a team -- when we win, we win together, and when we lose, we lose together."
Navas said everyone at the Bernabeu was "hurting" and "aware that we put in a very bad display."
"Both the players and the coaching staff take responsibility for their mistakes, and we know that there are aspects we have to change if we're to be successful," he added.
"We're out to fight to achieve the goals that we have in front of us. It's down to us, and over the remainder of the season we want to bounce back.
"We put in a bad performance, and that's something that you can never hide. We know what we have to change to be successful. People can say what they like, but what's important is what all of us think."
Navas, who missed the defeat to Sevilla before the international break through injury, said he was back to full fitness and praised the club's medical staff for doing "a great job."
Meanwhile, Shakhtar coach Mircea Lucescu backed under-pressure counterpart Rafa Benitez, who was given a vote of confidence by club president Florentino Perez on Monday.
Speaking at his prematch news conference, the Romanian said Madrid should keep faith with him.
"Before losing against Barcelona and Sevilla, Madrid were first in La Liga," he said.
"After two defeats, it is normal that there is pressure and that they blame him. But I believe they should back stability."