Champions League contenders Malaga were banned from European club competitions for one upcoming season by UEFA on Friday for failing to pay players wages and tax bills on time.
UEFA said the Qatari-owned Spanish club could be banned for a second season within the next four years if they miss a March 31 deadline to pay their debts, which are reported to include $11.6 million in unpaid player wages.
UEFA announced the sanctions on Friday, one day after Malaga were drawn to play FC Porto in the Champions League last-16 round. They will be barred from the first Champions League or Europa League tournament it qualifies for in the next four seasons.
UEFA's club finance judicial body also fined Malaga $396,000. The club can appeal the sanctions direct to the Court of Arbitration for Sport.
Malaga are set to collect around $33 million from UEFA in prize money and share of television revenues from playing in this year's Champions League.
Malaga qualified for world football's most prestigious club competition for the first time by finishing fourth in the Spanish league last season.
The club's rise was fuelled by a takeover by Qatari investor Sheik Abdullah Bin Nasser Al-Thani and a spending spree on players.
Malaga are currently fourth in the league which - before Friday's sanction - would have been enough to earn the right to play in the Champions League playoff round in August, needing to beat one opponent to enter the lucrative 32-team group stage.
Clubs must pay their football and tax debts as a condition of getting a license from their national association to play in UEFA competitions.
UEFA has enforced a licensing system for almost a decade, but the rules and potential sanctions have gained a higher profile in the 'Financial Fair Play' era.
Eight other European clubs were also punished on Friday by UEFA's Club Financial Control Body.
Five clubs - Bucharest clubs Dinamo and Rapid, Serbian club Partizan Belgrade, and Hajduk Split and Osijek of Croatia - face a one-year ban from European competiion within the next three years if they miss the March 31 deadline to settle debts.
Four of the clubs were also fined $160,000 each, and Hajduk was ordered to pay $130,000.