La Liga champions Barcelona host bitter rivals Real Madrid in the first Clasico of the season on Saturday, forced into leaning heavily on players from their feted La Masia youth academy.

An injury crisis has ravaged the Catalan club, leaving them without several key players, across defence, midfield and attack.

Last weekend 17-year-old striker Marc Guiu pulled Barcelona, third, a point behind leaders Real Madrid with a goal just 33 seconds into his debut, while Lamine Yamal and Fermin Lopez strikes secured comeback draws against Granada and Real Mallorca.

The first team already features several young players who spent time at the club at youth level, including midfielder Gavi and defenders Alejandro Balde and Ronald Araujo, but the current situation has further exacerbated Barcelona's dependence on the youth system.

Injured stars Robert Lewandowski, Frenkie de Jong and Raphinha are fighting to return to play at least some part in the game at the Olympic Stadium, but Jules Kounde, Pedri and Sergi Roberto are set to miss out.

Real Madrid have had some injury problems of their own, but defender Nacho Fernandez will be allowed to play after his three-match ban for a dangerous tackle was shortened to two.

England international Jude Bellingham, the division's top scorer with eight goals, is Madrid's leader, and his arrival for 103 million euros ($109 million) from Borussia Dortmund this summer was in stark contrast to Barcelona's activity.

Still mired in financial problems, Barcelona were limited to signing players on free transfers or on loan, along with a low-cost move for midfielder Oriol Romeu, to try and fill the big shoes of former captain Sergio Busquets.

"We're in a moment where we have to bet on players from here, and they are ready," Barca coach Xavi told reporters last week.

"When things don't go well, you have to double down on the bet, we have to bet on the youngsters, homegrown. I see they are hungry."

With Barcelona fragile, scraping by without various key players and failing to consistently find the good football Xavi admits is demanded of the club, Madrid have the chance to strike a morale blow against them by inflicting their first league defeat.

Los Blancos have not regularly found top gear yet either but have come closer to it.

"We know exactly what we need to do -- everything we can to win it," said Real Madrid coach Carlo Ancelotti.

"We're heading into this incredibly important game full of excitement."

As ever, the lead-up to the Clasico has not just been focussed on football.

Madrid have launched an apparent campaign against Spain's referees, with Real Madrid TV producing various videos attacking officials, sometimes before matches are even played.

At the same time Barcelona president Joan Laporta has claimed in recent weeks that there is 'sociological Madridismo' in Spain -- saying Real are favoured by the state.

Laporta has been charged with bribery in the 'Negreira case', an investigation into Barcelona's payments to a former refereeing chief, which the Barca president believes is an example of it.

A Barcelona spokesman has also caused a stir with a social media post seemingly dismissing recent racism aimed at Madrid winger Vinicius Junior, saying the Brazilian needs a "slap" and is a "clown" for his behaviour on the pitch.

According to Spanish reports, it has led to Madrid president Florentino Perez deciding to snub the Clasico in protest.

Both Xavi and his counterpart Carlo Ancelotti will each be hoping by the time the dust settles on Saturday night, the main topic of conversation will be their club's success.

Elsewhere in La Liga, second-place Girona host Celta Vigo on Friday, and could depose Madrid at the top of the table before the Clasico begins.

Atletico Madrid, fourth, welcome Alaves, 15th, on Sunday night.