The transfer ban imposed on Spanish La Liga side Atletico Madrid has thrown a spanner in Lyon's preparations for next season.
Lyon striker Alexandre Lacazette was on the verge of joining the Spanish club for a reported 60 million euros, but the deal taking the player to Atletico will no longer be happening.
"Of course, that has changed everything," Lyon president Jean-Michel Aulas was quoted by L'Equipe.
"This is bad news and good news. It was, in financial terms, a very significant transaction.
"We had given Alex the green light to go to Atletico, the club of his heart," Aulas said.
"I've not had his agent on the phone, nor him, as I've been in Cardiff (for the Women's Champions League final).
"But I had said to Alexandre not to get too far ahead of himself, as there can always be disappointments in football.
"It brings into question the commitments made on both sides. We had made progress on possible solutions."
Diego Simeone's side are unable to sign any players until January 1 next year, but Lyon could be tempted to sell the player, who has been heavily linked with Manchester United following the news of Atletico's transfer ban.