Diakite has been linked with Fiorentina this season.
"It is not a given that he will leave in January," representative Ulisse Savini told La Lazio Siamo Noi.
"The player is training with the squad and is doing so in a professional manner. It is obvious that he wants to play, but that hasn't happened up until now.
"But there are no agreements with any other clubs. That's just journalistic invention.