Metalist Kharkiv, due to play Schalke 04 in the Champions League play-off round next week, has been kicked out of the competition over a domestic match-fixing case dating back to 2008, the UEFA said on Wednesday.
The decision by UEFA's appeals committee came 10 days after Metalist lost an appeal at the Court of Arbitration for Sport.
Last year's Ukrainian league runners-up will be replaced by Greek side PAOK, the team they beat in the third qualifying round.
Metalist said they would appeal to CAS and a ruling in their favour, which may not come until after the group stage has started, could throw the Champions League into confusion.
"We regret that such a sanction was applied, and we do not agree with it, that's why today we plan to appeal to the Court of Arbitration for Sport in Lausanne," Metalist first vice-president Kostyantyn Pyvovarov said.
"Also, we have appealed to the Supreme Court of Switzerland with the application for suspension of CAS decision.
"I want to remind you that the match, which allegedly took place, was held back in 2008, with the old owners of the club. At the same time, Metalist has won the right to participate in the Champions League 2013/14 in a fair fight.
"Our team, our fans deserve to take part in the main football competition in Europe. I want to assure fans that we will fight for the rights of the club and protect them in accordance with all legal requirements."
Metalist's replacement PAOK will visit Schalke on August 21 with the return on August 27 for a place in the group stage. The UEFA's emergency panel decided to include the Greek side rather than hand Schalke a bye.
The panel also decided that PAOK would not be replaced in the Europa League qualifying round and their opponents Maccabi Tel Aviv would go straight into the group stage.
Metalist were not the only club whose Champions League participation was shrouded in uncertainty.
CAS has already allowed Fenerbahce back into the competition while it considers an appeal from the Turkish club against their two-year ban from European competition over a domestic match-fixing case.
CAS have said they will make a final ruling on Fenerbahce's case by August 28, the day after the Turks play the second leg of their playoff tie against Arsenal.
Fenerbahce have already eliminated Salzburg from the competition.
Earlier this month, CAS upheld a Ukraine Football Federation (FFU) decision to fine Metalist Kharkiv and FC Karpaty $25,000 each over the manipulation of a match played in April 2008.
The tribunal also confirmed bans of between three and five years on six Metalist players, plus fines of $10,000 each.
Metalist director Yevhen Krasnikov was banned from any soccer-related activity for five years.
Two Karpaty officials were given suspended bans and ordered to pay "compulsory cash contributions" to the FFU while CAS upheld an appeal by a third official from the club.
CAS said in its ruling that the two clubs "were held liable for the behaviour of their football players or officials under the principle of strict liability."
Image: FC Metalist Kharkiv supporters during the UEFA Europa League group stage match between FC Metalist Kharkiv and SK Rapid Wien on October 4, 2012 at the Metalist Stadium in Kharkiv, Ukraine.
Photograph: Genya Savilov/EuroFootball/Getty Images