Real Madrid boss Carlo Ancelotti hit out at the "crazy" football calendar which could see his side's South American players miss next month's Copa del Rey quarterfinals, but denied the club will put pressure on national teams to help resolve the situation.

Madrid could face Athletic Bilbao at San Mames in the cup on Feb. 3 with Vinicius Junior, Casemiro, Eder Militao, Rodrygo and Fede Valverde all absent.

- ESPN+ viewers' guide: LaLiga, Bundesliga, MLS, FA Cup, more
- Don't have ESPN? Get instant access

The four Brazilians have all been called up by national team coach Tite for matches with Ecuador and Paraguay, with the latter game being played at 1.30 a.m. Spanish time (7.30 p.m. ET) on Feb. 2, while Valverde is in the Uruguay squad to play Paraguay and Venezuela.

"The calendar doesn't make sense," Ancelotti said in a news conference on Saturday ahead of Real Madrid's LaLiga game with Elche. "But this isn't just a Real Madrid problem. It's a problem for every team. Other teams will be affected by these call-ups too.

"We won't put pressure on anyone. We'll play when we have to play, with the players who are here. But the calendar is crazy. It has to be fixed as soon as possible."

Brazil are already certain of a place at the 2022 World Cup -- they lead the South American qualifying group with 35 points from 13 games played -- while the participation of Valverde's Uruguay is in doubt.

Ancelotti said that Real Madrid will not try to exert any influence on Brazil to send some of their players home early, given their position in the standings.

"We know how much our Brazilian players want to play for their country," Ancelotti said. "They will go away with the national team and the Brazil coach will take his decisions, whether to pick the players or not, and then they will come back."

Real Madrid's Copa del Rey meeting with Athletic will be the fourth time the two sides have met in recent months.

Madrid won both league meetings in December, winning 1-0 at the Bernabeu and 2-1 at San Mames, before beating Athletic 2-0 in the Spanish Supercopa final in Saudi Arabia last Sunday.

Ancelotti's side are strong contenders to win this year's Copa del Rey after Barcelona, Atletico Madrid and Sevilla were all knocked out in the round of 16.