Copa del Rey holders Barcelona begin their defence of the trophy when they go to third-tier Villanovense for the first leg of their last-32 tie on Wednesday evening.

The match has been brought forward from the first midweek in December because of Barcelona's involvement in the Club World Cup in Japan at the end of the year, and so the Catalans make the trip to the small town of Villanueva de la Serena while the rest of La Liga enjoys a midweek off.

Still without the injured Lionel Messi, Barca coach Luis Enrique has also opted to rest the likes of Neymar, Luis Suarez, Gerard Pique, Sergio Busquets and Claudio Bravo for the game against opponents from the region of Extremadura in western Spain.

As a result, four players from Barca's B team, who like Villanovense compete in the Second Division B, have been promoted to the first team.

Midfielders Sergi Samper and Gerard Gumbau, both 20 and who have already featured for the first team, are included along with attacking duo Aitor Cantalapiedra and Wilfrid Kaptoum, both aged 19.

A slip-up would not be disastrous for Barca with the second leg to be played on December 2 at the Camp Nou, but Luis Enrique is prevented by competition rules from fielding too many reserve players.

"We are limited because we must always have seven first-team players on the field," he acknowledged.

"I would have liked to rely on more young players and give more of a rest to others."

Copa del Rey round of 32, first legs (ties involving top-tier teams)