David Moyes fears a Premier League injury pile-up if players are rushed back from coronavirus lockdown in a bid to complete the current season.
Authorities are still wrestling with the problem of how to finish the campaign in such a tight timescale, with clubs likely to need to play three games a week.
And while the West Ham boss wants a four-week training build-up once the restrictions ease, he acknowledged clubs are unlikely to get what they wish for - and could pay the price as a result.
Moyes said: "I think that four weeks would be ideal. But I think three weeks will be the maximum we get.
"Everybody's now talking about the injuries we're liable to pick up either during the three-week preparation time or during the period where it looks like we'll have to play an awful lot of games in a short period of time."
The Hammers will resume the campaign sitting above the relegation zone on goal difference.
However Moyes insisted he sees cause for optimism early in his second spell in charge, adding: "I want to build a new, energetic, young team and I think we've just started that.
"With the signings we've brought in January, trying to freshen it up and given us a lot more youthfulness and direction."