Manchester United have been heavily linked with a swoop for the young playmaker, who is available for £18m due to a clause in his contract which remains active until the end of July.
Thiago was limited to just 15 starts in La Liga last season, scoring two goals and making five assists as the Spain Under-21 international failed to dislodge the likes of Andrés Iniesta, Cesc Fàbregas and Xavi.
But Bayern sporting director Sammer rubbished reports the Champions League holders had agreed a deal for the 22-year-old.
“Why would we not communicate it if something was signed? No, of course that is not the case,” Thiago told German newspaper Bild am Sonntag.
On Friday, Pep Guardiola admitted he wanted to sign Thiago this summer after being officially unveiled as Bayern’s new manager.
“Yes,” Guardiola said.
“I don’t know what’s going to happen. We have to wait. I know him very, very well. He is a super, super player. He can play in three, four or five positions.”
He added: “It is either Thiago or nothing.”