Brazil legend Roberto Carlos has urged Chelsea to be wary that new signing Samuel Eto'o could have a negative impact on the Stamford Bridge dressing room, in an interview with Globoesporte.com.
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Carlos, 40, played alongside Eto'o at Anzhi Makhachkala prior to his retirement in 2012, before taking up a role as assistant and then technical director at the club.
The former Real Madrid left-back says the pair enjoyed a good relationship prior to working together at Anzhi -- they also played together briefly at the Bernabeu -- but that Eto'o's desire to exert control at the Russian club led to a rift between them.
Carlos, now manager of Turkish side Sivasspor, has revealed that Eto'o's arrival at Anzhi initially caused ructions in the dressing-room and also claimed he later considered quitting his role because the four-time African Footballer of the Year made life difficult for him.
"I've known Eto'o since he was 16. He's a good person and I've always liked him, but he always thinks of himself, not the group, which can be really damaging, "Eto'o told Globoesporte.com. "It's quite confusing and odd when a footballer, instead of playing, is interested in bringing in players who are his friends. He did everything at Anzhi, except play football.
"Because of the values involved [Eto'o was reportedly earning £300,000 a week at Anzhi], there were a few small problems in the dressing room with the arrival of Eto'o, which were resolved. His signing had to be explained to several players.
"Then there came a point when Samuel wanted to interfere in my work. He wanted to control the club, taking my place and that of the coach, Guus Hiddink. We talked about one thing, and then he went to the players and talked about another. That stressed me out and I warned that I would pack my bags and go."
Despite the warning, Chelsea boss Jose Mourinho will believe he can bring the best out of a player who starred under him at Inter Milan, helping the club win the Treble in 2009-10.
Eto'o is expected to make his debut for the Blues this Saturday against Everton.