Carlo Ancelotti criticised the state of Cacereno's pitch after his Real Madrid side's hard-fought 1-0 Copa del Rey victory on Tuesday, saying "you can't play football" on surfaces like that.
Madrid's fourth-tier opponents put up a stubborn performance against the European and LaLiga champions, but a superb 69th-minute strike from Rodrygo was enough to see Ancelotti's side into the round of 16.
The poor standard of the surface at Estadio Principe Felipe made it difficult for Madrid to get going as they made hard work of avoiding a massive upset.
Ancelotti was frustrated with the quality of the turf, telling reporters: "You can't play football. For me it's not football, it's another sport.
"It's nice because small teams can fight and compete with bigger teams. It's good for the fans, but the fans also want to see nice games."
Despite Madrid's lacklustre performance against a team three leagues below them, Ancelotti was content with how his team played, saying: "Rodrygo made a fantastic play, the rest was an even and competitive game.
"A lot of struggle, a lot of long balls, it couldn't be done any other way. The team has complied and I'm satisfied, it was a game we're not used to.
"I liked everything, from the first minute to the last, I knew we had to suffer. We didn't risk anything, the line of defence was fine, a clean sheet, everything was fine."
While Ancelotti was unhappy with the standard of Cacereno's pitch, he was complimentary of their team, adding: "They played very well.
"They pressed high up, we didn't have the chance to handle the ball well."