Coach Zinedine Zidane has slammed as "absurd" a one-year transfer ban imposed on Real Madrid by FIFA for irregularities in the signing of foreign players under 18.

The Frenchman's own children are among those part of the case against the European champions.

FIFA dismissed Real and local rivals Atletico Madrid's appeals against a two transfer window ban on Thursday, meaning they won't be able to register any new players until January 2018 unless further appeals to the Court of Arbitration for Sport are successful.

Two of Zidane's four sons who play in the Madrid academy were among 39 players investigated by FIFA with the club eventually sanctioned for breaking the rules regarding the signing of foreign nationals under 18 in eight cases.

"I don't understand it at all and it bothers me," Zidane said on Friday ahead of Madrid's clash with Osasuna.

"I can talk about my (sons) that have been born and lived their whole lives here. It is absurd that they can't play football.

"What we are going to do now is wait and hope that this subject is fixed as quickly as possible."

Under international football rules, players under 18 cannot be transferred to another country, except in limited circumstances, and all transfers need the approval of a special FIFA committee.

However, Zidane's sons appear to meet those criteria as the former World Player of the Year's family has largely been based in the Spanish capital since he signed for Real as a player in 2001.

On the field, Zidane can continue his incredible first year as a senior coach as having lifted the Champions League in May, Real can match a club record of 15 consecutive La Liga wins at the Santiago Bernabeu on Saturday.