Panathinaikos have been banned from European competition for three years by the continent’s football governing body after failing to pay their debts.
Players at Greece’s oldest club went on strike earlier this month in protest over unpaid wages from last year.
The 20-time Greek champions were given a suspended sentence by Uefa in December, and told they had until 1 March to settle their unpaid bills.
Having failed to comply, they have also been fined 100,000 euros (£88,000).
Panathinaikos, who are seventh in Greece’s top flight, had already incurred a three-point domestic penalty this season for failing to pay money owed to their former defender Jens Wemmer.
The Athens-based club are the country’s most successful side in European competition. They were European Cup runners-up in 1971 and reached the semi-finals of the same competition in 1985 and 1996, losing to Liverpool and Ajax respectively.
This season, though, they were knocked out of the Europa League in the play-off round.
The punishment handed down by Uefa’s club financial control body represents another inauspicious moment for Greek Super League clubs this season.
Last month, PAOK Salonika president Ivan Savvidis was banned for three years for coming onto the pitch with a gun during a top-flight game against AEK Athens.