Luka Modric has challenged Real Madrid to restore their team ethic and tie up Pool A against Shakhtar Donetsk on Wednesday.
The former Tottenham midfielder admitted Real abandoned their hard-grafting principles in the damaging 4-0 El Clasico defeat to Barcelona on Saturday.
Boss Rafa Benitez continues to fight for his future despite receiving Real president Florentino Perez's backing, but Modric believes the current squad can still provide solutions.
Real can secure top spot in Pool A with a round of Champions League fixtures still to play with victory in Donetsk, and Modric accepts it is his side's sole starting-point after the weekend's crushing loss.
"When we play as a team and we all fight hard, we're a really good side," Modric told Real Madrid's official club website.
"We don't think it's an attitude problem, but we don't know the reason.
"We didn't play as a team, and if you're not compact against Barcelona that's what happens.
"This is not the first time this has happened so we have to pick ourselves up and improve."
Madrid captain Sergio Ramos misses out with shoulder trouble, while Marcelo suffered a groin injury against Barcelona.
Shakhtar will be without suspended defensive duo Olexandr Kucher and Darijo Srna, and must pull off an unlikely victory to keep their slim hopes of progression alive.
"Now we have to show character," said Modric.
"We're Real Madrid and we can't give in. We have to get ourselves out of this situation.
"It's a difficult moment for us. We didn't expect to lose and play so badly.
"We have to learn from our mistakes."
Shakhtar defender Vasyl Kobin hopes his side can heap pressure on Karim Benzema, to compound the France striker's lack of form.
Benzema was singled out for criticism in the Barcelona loss, and was then the only starting player back in training on Monday.
Kobin believes Shakhtar can exploit the situation in their bid for an unlikely upset.
"Karim is their main striker. The entire game is built around him, Ronaldo and Bale," Kobin said on the club's official website.
"It's good for us because they do not have an appropriate substitute.
"Madrid play more defensively (under Benitez). Previously they focused solely on attacking, but under the current mentor they drop deep and play on the counter more frequently."
Source: PA-WIRE
