Charlton Athletic manager Lee Bowyer says three players have not returned to training with the rest of the squad because of the coronavirus pandemic.
Several Championship clubs have been back in training since Monday, although there is no confirmed restart date for the 2019-20 season.
Bowyer spoke to BBC Radio 5 Live before the English Football League published results of the latest round of testing.
Three people tested positive from a total of 1,030 tests carried out.
Those tests were conducted between Monday and Wednesday, with tests last week returning two positive results from a total of 1,014 carried out - both of them at Hull City.
Bowyer said: "I met the players on Saturday before we'd done our first test and I asked them all individually 'it's your choice, do you want to come back and play the remainder of the season?'
"I've asked every single player and I said 'there's no pressure, it's your choice'.
"I understand everyone has got different circumstances, of course I'd rather everybody came back because the more players you've got, the bigger squad you've got and the more chance of winning games, but that isn't the case and we'll have to adapt.
"I'm sure there's other players at other teams that have also said 'no'."
Bowyer says he does not know if there are implications for players' contracts if they decide not to return to Charlton’s Sparrows Lane training base.
“That’s something that we’ll have to look into, but as it stands all I'm concentrating on is trying to get this group of players who have said 'yes' ready for the first game,” the 43-year-old said.
”So contract-wise behind the scenes, that’s not for me to decide, that’s for the club.”
The domestic season has been suspended since 13 March because of the pandemic and lockdown restrictions in England.
Championship clubs have returned to training in small groups, in accordance with the EFL's safety guidance and training protocols, with Charlton running three simultaneous sessions for three groups of five, with a further 10 players training afterwards.
Charlton dropped into the relegation zone just before the campaign was halted, and are two points away from safety.
Bowyer is keen to complete the season, but says this would be the case even if the Addicks were not threatened by the drop into the third tier.
“It is unlucky the way it’s fallen, but even if we weren't in the bottom three I would have still been just as eager to finish the season,” he said.
“I think it's the right thing to do because when you sign up to a season, you sign up to a 46-game season and we've only played 37.
"The right thing to do is try to finish the season - but when it's safe.
"And that's what the EFL want to do. I’ve been on a managers' call and they said that the bar is to finish the season and I'm on board with that."