Bayern Munich defender Lucas Hernandez fears it will be "impossible" to complete this season's Champions League.
UEFA has suspended the Champions League and Europa League indefinitely during the coronavirus pandemic.
President Aleksander Ceferin said last week that he would consider allowing those European competitions to resume behind closed doors if necessary, likely in July and August, but he accepted they might have to be cancelled if they were unable to resume matches by September.
With Europe's top leagues also facing the prospect of having to be completed in July or later, Hernandez does not think it will be practical to stage the final rounds of the Champions League at the same time.
"It's going to be hard to cram all this in as well as a possible end to the league," he told L'Equipe.
"The Champions League concerns all the countries affected by coronavirus. It will be difficult to get everyone out of lockdown, to be in similar condition but also just to meet up, to travel to Italy, Spain, England or France.
"You have to be realistic. I think it will be impossible to finish in the Champions League in these times, especially if we favour ending the domestic leagues."
Clubs in the Bundesliga have been allowed to resume first-team training, albeit with strict restrictions in place on the number of players assembled at any one time.
Bayern kept players in separate small groups to adhere to social distancing guidelines after beginning training at Sabener Strasse from last Monday.
"The conditions are very strict. We are in small groups of four. We do not meet the others," Hernandez explained.
"We train at different times to avoid contact. The changing rooms are also arranged differently. We don't occupy the same pitches.
"But as soon as it's over, we'll quickly go and shower and eat at home. This is another way to get the machine up and running again."