Barcelona boss Gerardo Martino has warned his players that Sunday's Clasico will be their "last chance" to stay in the Liga title race.
Victory for Real Madrid at Santiago Bernabeu would see them open up a seven-point lead over the current Spanish champions with just nine rounds of matches remaining, and Martino admits his side's title defence could be over should they lose the match.
"This is the last chance we have. After this round there are nine games left and cutting the gap to one point is not the same as it remaining four or [growing to] seven. In these final rounds teams don't falter so often," he told a press conference on Saturday.
Martino went on to stress that Barca's approach to the match would effectively be much the same as it would for any other encounter - although he did admit they would need to find a way to stop Cristiano Ronaldo.
"In a sense there is nothing different in what we have to do. It's true we have to close the gap, but we also know the situation well, because what we have to do in every game is to go out with the intention to win," he continued.
"I understand we must play well in possession and leave no gaps to allow Real Madrid to counter. We have to control Cristiano Ronaldo.
"The perfect game will come from the defensive side of the team."
Barcelona were pitted against Atletico Madrid in Friday's Champions League quarter-final draw, and Martino has acknowledged the danger posed by Diego Simeone's side.
"In the Champions League we've drawn one of the top three teams in Europe," he added.
"We've played very good games away from home, we will try to think of what we did in Manchester and not what we did in Valladolid, and point to that type of performance."