Carlos, 28, has been a key figure for the La Liga outfit this term, missing just one league fixture due to suspension.
Newcastle are keen to land the Brazilian centre-back this month as they look to shore up their defence for the second-half of the campaign.
But Daily Star Sport understands Sevilla are ready to play hardball when it comes to selling the player, who has not asked to leave the club despite recent transfer interest.
The Magpies have had a £25m offer turned down by the Spanish outfit in recent days – and will have to pay close to double that if they are to secure a deal before the end of January.
Sevilla’s stance is clear. They are desperate to hold on to Carlos until at least the end of the season as they hunt down Real Madrid in the fight for the title.
Sources close to recent talks insist the player himself has not expressed any desire to leave.
Sevilla have turned down bids for the former Nantes star in the past and are confident they will be able to fend off Eddie Howe’s cash-laden side.
Liverpool made their interest clear when pursuing Carlos for over 12 months a few years back.
The Reds ended up signing Ibrahim Konate in defence but saw the South American defender as the ideal partner for Virgil van Dijk once upon a time.
Carlos is just one of many names being touted as a January target on Tyneside.
Bournemouth’s Lloyd Kelly has an admirer in Toon boss Howe, while Arsenal’s Rob Holding could be another, cheaper alternative.
Newcastle attempted to secure a loan deal for the Gunners defender in August.
The Magpies are set to unveil first January signing, Kieran Trippier, in the coming days.
The former Tottenham defender was spotted at the club’s training ground on Wednesday after jetting in from Madrid.
Trippier will join the North East outfit in a deal worth an initial £12m.