Spanish Football Federation president Luis Rubiales says the domestic Supercup between Barcelona and Sevilla is most likely to be played on August 12 as a one-off fixture and not a two-legged affair as in the past.

La Liga and Copa del Rey champions Barcelona will take on Sevilla, the cup runners-up, in the Spanish Supercup, the traditional curtain raiser to the season. Sevilla finished seventh in La Liga and will be involved in the Europa League qualifying phases in August.

"I've spoken to FC Barcelona and to Sevilla in recent days and they have transmitted to me that considering the tight calendar, they were both prepared to play the Supercup as a one-off fixture," Rubiales told Cadena Ser radio.

"But we have a TV contract signed in which the Supercup was going to be a two-legged tie and we have to find a way to compensate them. If we succeed to reach an agreement with TV, then the Spanish Supercup is most likely to be played on Aug. 12 at a neutral ground in a one-off fixture as an exceptional measure. From next season, we will revert to the two-legged system."

Rubiales also spoke about Spain's World Cup and praised all of his players, including goalkeeper David De Gea. The Manchester United goalkeeper has received criticism for his performances in Russia. Spain have given away five goals from six shots in the group stages and there are calls for Spain coach Fernando Hierro to bring in Kepa Arrizabalaga in place of De Gea.

However, Rubiales said: "De Gea's issue is a sporting one and it's not for me to talk about that. All I can say is that we are very lucky to have the three goalkeepers that we have. We are very proud of all of our players. I would give them a 10 out of 10. There's no need to back the players as they know fully well what they are playing for. We have to be positive."

Spain take on hosts Russia in Sunday's round of 16 showdown in Moscow's Luzhniki Stadium and Rubiales is optimistic.

"Our aim? The only thing that I want is to be proud of my national team," he said. "We just have to go step by step. The players are doing a good job and our hopes remain intact, which is the most important thing. The fact that Germany have gone out of the competition shows that there is no small team and that it's not easy to advance."

Rubiales refused to comment on whether Hierro will continue at the helm of the national team after the World Cup.

Hierro replaced Julen Lopetegui, who was sacked three days before the start of the tournament in Russia. "It's an issue of the (RFEF's) executive committee as has always been the case," Rubiales said. "Fernando is very focused on the next game and doesn't want to talk about this right now. We have a crucial game against a top rival.

"Fernando's concentration is only on this. We have to be prepared for every challenge and the players are fully focused on the game against Russia."