Reports have suggested that Sissoko could be on his way out of the Ligue 1 club, with Tottenham, Arsenal and Newcastle touted as possible destinations.
However, Guerra refused to comment on any rumours linking the 23-year-old with a transfer, stating that the midfielder is “a Toulouse man”.
"I do not want to speak about it," Guerra told Goal.com. "I don't want to refer to any news stories for the moment. Moussa is a Toulouse man."
And far from Sissoko leaving the club, Guerra revealed that talks between Sissoko’s representatives and Toulouse have begun over a new contract.
He said: “Discussions have begun, I don't want to talk about an exit or respond to any rumours."
Sissoko joined Toulouse in 2007 and has scored 20 goals in 183 appearances for the French side, appearing 17 times and scoring once this season.
The midfielder has also won five caps for the France national team.