Casemiro believes Real Madrid have the attacking threat to "wreak real havoc" this season even if they do not sign Kylian Mbappe from Monaco.
Madrid have been heavily linked with a move for the 18-year-old after an astonishing 2016-17 campaign that saw him score 26 goals in all competitions for Leonardo Jardim's side.
Spanish newspaper Marca have claimed the Spanish and European champions have struck up a world-record EUR180million deal for Mbappe, which would dwarf the EUR105m Manchester United paid Juventus for Paul Pogba.
Monaco have denied any such deal is in place for their prize asset, who has been touted as a potential target for a host of Europe's biggest clubs during the transfer window.
And Casemiro says, while he is aware of Mbappe's talents, he does not believe Madrid need him given Zinedine Zidane has the likes of Cristiano Ronaldo, Gareth Bale, Karim Benzema, Isco and Lucas Vazquez at his disposal.
"These are things that people outside the club talk about," he said when asked about Mbappe at a media conference on Tuesday.
"He's not a Real Madrid player and I can't comment on any player who doesn't belong to Real Madrid.
"We're aware that he's a great player, but we've also got the BBC [Bale, Benzema and Cristiano], who can wreak real havoc.
"The more players we have, the better it is for us. That said, the best players are already here.
"We know all about the quality that players like Mbappe, Neymar... possess, but I've got to talk about our players.
"We've got the world's greatest player [Ronaldo], then there's Bale - who's working very hard - and Karim, who has great quality, Isco, Borja [Mayoral]...I'll back our players to the hilt."