Despite being a key in Juve's success over the past few years, Mandzukic now finds himself deemed surplus to requirements after the club decided against selling Gonzalo Higuain.
The Croatian has not played a single game under Sarri this season and was also omitted from the side's UEFA Champions League squad.
"Mandzukic is not training with us, in agreement with the club," Sarri was quoted as saying by the Mirror.
"If the agreement changes, I am open to everything."
Sporting director Fabio Paratici revealed earlier this week that he has met with the veteran forward to discuss his future.
"With Mandzukic, we chose a quiet time for him to leave but a move to Qatar [in the summer] did not materialise so he stayed with us," Paratici said.
"Now we will talk to him and see what happens in January.
"We are evaluating, he is also evaluating. We need maximum calm, he is a great player.
"It has been an added value in recent years, we must thank him. If he considers it appropriate to leave, we will satisfy him, otherwise he will consider other solutions."
