Carlos warns Chelsea over Eto'o influence
The pair played together while at Russian side Anzhi Makhachkala, with Carlos joining the club first as a player before moving to form part of Guus Hiddink's backroom staff.
Eto'o was brought in from Inter on a lucrative package in 2011 but Carlos - who has since left the Russian outfit, along with Hiddink, following a cost-cutting exercise over the close-season - believes that the Cameroon international can be a disruptive influence.
"I've known Eto'o since I was 16, and from that time on he's always been a good guy who I've liked a lot," Carlos told Globo.
"He's a good person, but there's a part of him that thinks 'I, and not the group', which is really damaging.
"When a footballer, instead of playing, is interested in signing players who are his friends... it's confusing and strange.
"He did everything at Anzhi, except play football."
Carlos added that the management team's control over the squad began to dwindle when first Eto'o arrived.
"We managed to professionalise the team. In the second year, we signed Eto'o and I had control of the team - I organised the players and worked with the coach. I put Anzhi among the best," he continued.
"With the arrival of Eto'o, with the values of everyone involved, I had some little problems in the dressing room and had to talk to the Russian players and explain why Eto'o was there.
"However, a moment arrived when Eto'o thought to interfere with my work, to control the club, taking my position and that of Guus (Hiddink)."
Eto'o moved to Chelsea in August on a one-year deal, linking up with his former boss at Inter, Jose Mourinho.