MADRID, Oct. 25 (Xinhua) -- Real Madrid plays FC Barcelona on Sunday in the first Clasico of the season which will lay down a marker for both sides.

Madrid goes into the game top of La Liga having thus far played functional rather than attractive football, with Kylian Mbappe making the difference in many games.

Although just two points behind, Barcelona has shown erratic form, with some excellent attacking displays unbalanced by a defense that looks more vulnerable than last season, partly due to Inigo Martinez's departure to Saudi Arabia.

Barcelona has been plagued by injuries in recent weeks, with Lamine Yamal struggling with a pelvic problem, which is almost certainly the result of the amount of football he has played over the past year. Elsewhere in the squad, Raphinha is still out with a hamstring issue, Robert Lewandowski and Dani Olmo have calf injuries, Joan Garcia and Gavi have knee problems, while Ferran Torres suffered muscle fatigue with Spain's national team, but should start on Sunday.

Frenkie de Jong should also play despite suffering a stomach bug during the week.

To make matters worse, Barcelona coach Hansi Flick will be watching the match from the stands after being sent off in his side's late win over Girona last weekend and seeing all of the club's appeals rejected.

Although Barcelona won last weekend, that game may give Madrid an insight into how to beat Flick's side, as Girona found space to thread the ball behind Barcelona's high defensive line. Barcelona has to get its pressing right otherwise Mbappe, Vinicius Jr and Fede Valverde will find the gaps in its defense.

Mbappe has been in outstanding form this season with five goals in Europe and 10 in La Liga, and along with Vinicius Jr, Arda Guler and Jude Bellingham, he carries Madrid's threat in attack. ■