MADRID, Jan. 8 (Xinhua) -- Real Madrid coach Santiago Solari on Tuesday asked for the rules regarding the use of the Video Assistant Referee (VAR) system to be clarified in Spain.

Solari was speaking two days after his side were not awarded a penalty following a challenge by Real Sociedad goalkeeper, Geronimo Rulli on Vinicius Jr during Madrid's 2-0 home defeat to Real Sociedad on Sunday.

Images are unclear whether or not a penalty should have been given, but Solari was annoyed the referee didn't stop the game to look at the images.

"For me, as a spectator, I don't understand the way it (VAR) works on occasions," commented Solari in a press conference ahead of Wednesday's Copa del Rey last 16 tie at home to Leganes.

The VAR will be used for the first time in the Copa during the round of matches which will be played over the next week and Solari said he was happy to have the system used, but "it all depends on the rules being clearer than the technology."

"They will perfect it," he said, adding that he was not complaining about the VAR, but the club was "defending ourselves, which is our right."

With Madrid 10 points behind Barca in the Liga Santander, the Copa del Rey perhaps offers their best hopes of a title this season.

"We place the same importance on every competition," said Solari, who didn't rule out handing a debut to new signing Brahim Diaz, who arrived on Monday.

"He looks very good and he's happy to be here," he commented about the 19-year-old.

Finally he refused to discuss photographs which show Gareth Bale (who is currently injured) leaving the Bernabeu 10 minutes before the end of Sunday's defeat. "We will solve these things in private," was all Solari would say.