European champions Real Madrid picked up a record fifth trophy of the year to cap a fine 2017 at the Club World Cup last weekend, but trail Barca by a mammoth 11 points at the top of La Liga albeit with a game in hand.
Real Madrid's Cristiano Ronaldo is ready to start Saturday's clash against Barcelona, where his side could either reignite their title defence or effectively be knocked out of the running.
Ronaldo had been absent from training after hurting his calf against Gremio in the Club World Cup final last Saturday, in which he scored the only goal of Real's 1-0 win over the Brazilian side and completed the full 90 minutes.
"He is feeling good and is 100 percent," coach Zinedine Zidane told a news conference on Friday.
Ronaldo is having his worst domestic campaign in nine seasons with Real, having scored only four league goals so far, although he goes into the 'Clasico' having scored five times in his last four games in all competitions.
Real are fourth in the Liga standings, 11 points adrift of leaders Barca, who have played one game more.
A win in Saturday's lunchtime kick off at the Santiago Bernabeu would offer the champions the chance to cut the gap with Barca to five points if they win their game in hand against Leganes.
Defeat, however, would see them slip a remarkable 14 points behind.
"We aren't feeling anxious, it doesn't matter how many points we have dropped this season, now we have to put in a great performance against a very good side," said Zidane.
"It doesn't matter if Barca have played well or not this season, they are top on their own merits and for a reason. We are behind them and we want to cut that gap down. If we play well we can cause any team problems."
Barca coach Ernesto Valverde said the enormous gap in points between the two sides would have little bearing on the game.
"I don't think we are favourites, the league table has no influence on games like this because of the tension there always is," he said.
"Madrid are such a powerful team that they can strike you down even when you're in your best moment of form. Also, they will be at home."
Real outclassed Barca in the last 'Clasico' in the Spanish Super Cup back in August, winning 2-0 in the second leg at the Bernabeu to complete a resounding 5-1 victory on aggregate.
The two teams have had contrasting results in the league since, however, with Barca going unbeaten in 24 games in all competitions and taking a six-point lead at the top of La Liga over nearest challengers Atletico Madrid.
"We are very excited about the game, we're keen to vindicate ourselves after the Super Cup and to measure ourselves up against them. Both sides go into the game in good form and I think we're ready," Valverde said.
Zidane added: "It will be the most difficult game of the season, these are always exciting and hard games but that's how we like them. Players live for games like these."