Lyon goalkeeper Anthony Lopes' ear drums were not permanently damaged by firecrackers thrown at him by Metz fans, the Ligue 1 club have said.
Lopes, 26, could miss Lyon's crucial Champions League game against Sevilla in Spain on Wednesday as a result of the incident, which led to Saturday's Ligue 1 game being abandoned after 31 minutes with Metz leading 1-0.
"Fortunately his eardrums weren't affected by the firecrackers. However, Dr. [Christian] Giroud confirmed that there was some traumatic hearing loss in both ears, a diagnosis first made yesterday evening by the emergency room staff at the Mercy de Metz hospital where the player was taken," a Lyon club statement read.
"The emergency room doctors in Metz advised that Lopes is temporarily unfit to play, a view confirmed this morning by Dr Giroud, who has already prescribed a course of treatment that will take some weeks.
"Over the coming days, the club will provide updates on the progress of Lopes's condition. The keeper also has to overcome the psychological trauma caused by this odious aggression, which may also have physically affected Metz captain Guido Milan as well as [Lyon captain] Maxime Gonalons."
An 11th-hour decision will be taken on Lopes' participation in the Group H decider at Parc OL where Lyon need to win by a two-goal margin to progress to the knockout stages at Sevilla's expense.
The statement added that Dr Emmanuel Orhant, who was attending to Lopes when further firecrackers were thrown at the prone Portugal international goalkeeper, was not physically injured.
"OL emphasises that the whole squad and staff stand with Lopes in being deeply shocked at this act of aggression, which the club once more denounces in the strongest possible terms," the statement concluded.
The French Football League (LFP) will receive the official reports on the incident on Monday, and will make a decision on whether Lyon should be awarded a 3-0 victory by default or whether the game should be replayed.
"The incidents that occurred on Saturday night at the Stade Saint-Symphorien are absolutely unacceptable," a statement from Metz president Bernard Serin read on the club's official website.
Serin promised "an arsenal of strong and radical measures" to ensure such incidents are not repeated at his club's home. He also called on the LFP to order the game replayed "as has always been the case with matches interrupted before the end for this kind of incident."