Carlos previously played with Boral while at Fenerbahce.
Speaking at a press conference Carlos said, “This hasn’t been brought to my attention by the club so i cannot comment on it. Boral is a good friend of mine and is a good player.
“I have provided a list to the clubs management of players which I would like in January. We hope to be challenging for European football come the end of the season.”
Boral’s contract runs out at the end of the season and is looking for a move away from Besiktas having not played any first team football this season.
The 32-year-old has previously played for Fenerbahce, Kocaelispor, Ankaraspor and Gençlerbirliği.
Sivasspor who finished last season far beyond expectations in fifth place, currently find themselves in 17th place with only one win in nine games this season.