John Textor admitted he was worried about whether Crystal Palace would be able to play in the Europa League from the moment they won last season's FA Cup.
Textor's continued involvement at Lyon and Palace as of March 1 this year looks set to cost the Eagles a place in Europe's second-tier competition under UEFA's rules governing multi-club ownership, with Nottingham Forest then likely to replace Palace in the Europa League.
The American, who has agreed to sell his stake in the London club to New York Jets owner Woody Johnson, told talkSPORT he immediately realised the issues Palace might face.
"I couldn't have been happier for the fans, but I was worried about what was coming there," he said.
Asked what he was thinking as Palace beat Manchester City at Wembley, Textor said: "Oh s***, is what I thought.
"I was very happy, but I felt the gravity of it. And I was concerned on the same day holding the cup next to the Prince (William)."
Palace's prospects of playing in the Europa League appeared to recede on Wednesday when Lyon won an appeal against their relegation to the French second division due to financial issues.
Lyon had agreed a settlement with UEFA to be barred from European competition if the appeal was dismissed but are now set to play in Europe next season.
Under multi-club ownership rules, clubs wishing to be eligible for qualification in 2025-26 had to be able to demonstrate that, as of March 1, no individual or legal entity had control or influence over more than one club participating in the same competition.
Where two or more clubs fail to meet the criteria, only one can be entered. Lyon's higher league position would give them priority over Palace.
Sources close to UEFA on June 30 indicated no multi-club ownership issue had been identified with regard to Palace shareholder David Blitzer's involvement with Danish side Brondby, who have qualified for the Conference League, which means the London club should face no barrier to entering UEFA's third-tier club competition.
UEFA's club financial control body is set to make a final ruling on the Palace-Lyon case later this week or early next week at the latest.
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