Luka Modric has joined boss Zinedine Zidane in acknowledging that Real Madrid "lacked confidence" during their 3-2 defeat against Shakhtar Donetsk.
Although Los Blancos improved during the second half, conceding three first-half goals ultimately cost them in their first game of the Champions League group stages.
Modric, who got on the scoresheet shortly after the restart, told reporters after the game in Spain's capital that Real's performance was "not worthy" of European football's premier competition.
The 35-year-old said: "In the first half we were not worthy of this competition. It's obvious we need to improve, we lacked confidence today, especially in the first half, but we have to move on, we can't waste any time regretting what has happened."
The defeat on Wednesday evening came four days after the La Liga champions lost out at home to top-flight newcomers Cadiz.
Real are next in action when they square off against Barcelona on Saturday.