Mallorca finished fifth in La Liga last campaign and qualified for the Europa League but UEFA said on Thursday it had decided the club had not fulfilled the admission criteria as the requisite licence had not been granted.
UEFA did not explain the reasons behind the decision but Mallorca said in May they had applied to go into voluntary administration in an effort to sort out their finances.
"...the licence of the club was not granted in accordance with the UEFA Club Licensing Regulations, 2008 edition, and the club has not fulfilled its obligations as defined in these regulations," UEFA said in a statement on its website.
The club's lawyer, Luis Huerta, said in a statement on Friday an appeal would be lodged once more was known about UEFA's decision.
Huerta noted that the Spanish judge overseeing Mallorca's administration process had asked UEFA and the domestic football federation (RFEF) not to revoke the club's licence as this would complicate the financial reorganisation effort.
"This (UEFA) decision is seriously harmful to the club's administration process as there were a series of revenues expected ... that would have allowed payments to creditors," Huerta added.
"I am optimistic," Laudrup said on the club's website on Friday. "It doesn't seem logical that this could happen. I don't think we'll stay out."
