Barcelona's Gavi will set a Clasico record after he was named in Ronald Koeman's side to take on Real Madrid at Camp Nou.
Gavi became Spain's youngest ever player this month, impressing in a Nations League semi-final win over Italy.
At the age of 17 years and 80 days, the midfielder, who was named alongside Sergio Busquets and Frenkie de Jong, will be the youngest player to start a Clasico match since the turn of the century.
Ahead of Gavi, Ansu Fati, who has scored twice in LaLiga since returning from a long injury lay-off, was given his second start of the season in Spain's top flight, with Sergino Dest and Memphis Depay completing Barca's frontline.
Fati, who inherited Lionel Messi's number 10 jersey at Barca, is still the youngest player to appear in a LaLiga Clasico this century, having made his debut in the fixture at the age of 17 years and 48 days in December 2019.
Gerard Pique lined up alongside Oscar Mingueza and Eric Garcia in a possible three-man defence, with Jordi Alba on the left flank.
Sergio Aguero, who made cameo appearances in Barca's past two games, was named on the bench again.
Madrid went into the game looking to win twice in a row at Camp Nou in LaLiga for just the third time, and Carlo Ancelotti's side had plenty of Clasico experience in their ranks.
Ballon d'Or hopeful Karim Benzema was selected up top, with Casemiro, Toni Kroos and Luka Modric in midfield. David Alaba was handed a Clasico debut in defence.
Madrid went into Sunday's game on the back of a 1-0 defeat to Barca's city rivals Espanyol. They have not suffered back-to-back defeats in LaLiga since 2018-19.