Sporting Gijon insist Birmingham target Michel will not be leaving for less than his current value.
Michel has emerged as a target for Alex McLeish as he continues his attempts to strengthen his St Andrews squad.
Reports have claimed the Blues wanted to take the midfielder on trial before firming up their interest, but Sporting have refused that proposal.
And Sporting president Manuel Vega does not want to lose the 23-year-old in a cut-price deal, with Michel reportedly valued in the £2.5million bracket.
"Michel's exit will only be possible if an offer arrives for his value," Vega told the Spanish media.
Michel has come through the ranks at Sporting and was wanted by Bolton last year, but the Spanish side were reluctant to cash in at the time.
Birmingham will get the chance to take a closer look at Michel next weekend with Sporting due to visit St Andrews for a pre-season friendly.