Blues boss Maurizio Sarri is a fan of the attacker and would welcome his arrival in January.
Last month, Bailey revealed the Blues and Liverpool had made enquiries about him.
He said: “There's concrete interest.
“What I can say is that my full focus is on developing myself as a young player, and that's what I'll focus on.
“If a club wants me, my management and Bayer 04 will take care of it."
It is said Maurizio Sarri could strike a deal in January providing an offer of €60m bid is tabled.