The 22 year-old Bulgarian, however, is now eyeing a return to England after qualifying for a UK work permit.
He told Darik radio: "Liverpool is a massive club.
"It was then impossible for a work permit but that should not be a problem now because I play in the national team.
"I definitely think it is realistic (to return to England)."
Mihaylov revealed Liverpool have first option on him.
"This option comes from the time that Rafael Benítez was the head coach," added Mihaylov.