The head of global players' union FIFPro has given his backing to footballers who do not want to return to training because of coronavirus fears and cautioned that it would be "inhumane and unacceptable" if they were to be punished for taking such a stance.

Jonas Baer-Hoffmann's comments came after Troy Deeney of English Premier League side Watford refused to restart training ahead of a possible resumption of the season because he does not want to put his young child, who has breathing difficulties, at risk of catching the virus.

Deeney has also cited fears his family could be in danger because of figures that show black and ethnic minorities in the UK -- which has the highest recorded death toll in Europe -- are more likely to become seriously ill with COVID-19.

Deeney is "a player who has very legitimate concerns and wants to protect his family", Baer-Hoffmann said in a conference call with reporters on Wednesday.

"If these players are being pressured or potentially facing disciplinary actions, we feel that is very much unacceptable.

"The idea that somebody may be punished in a pandemic for trying to protect his family's health is inhumane and unacceptable."

However, there is no suggestion that Watford are planning to take disciplinary action against Deeney.

Several players in England have voiced concerns about returning to training, even in small groups.

Watford were among the Premier League clubs affected by six positive tests for the virus out of a total of 748 tests conducted on Sunday and Monday.

However, Liverpool manager Jurgen Klopp insisted none of his players were being forced to come back to training as the Premier League leaders started to work in small groups on Wednesday.

"It is the players' choice and that is clear," Klopp told Sky Sports.

"I said before the session, 'You are here on free will. Usually you sign a contract and you have to be in when I tell you, but in this case if you don't feel safe, you don't have to be here'."

"There are no restrictions, no punishment, nothing. It's their own decision and we respect that 100 per cent," he added.

England defender Danny Rose, on loan at Newcastle United from Tottenham Hotspur, had earlier said players were being treated like "lab rats" as the league attempts to get going again.

Baer-Hoffmann backed Rose, calling for discussions to take place involving players if they wanted "stricter rules".

"No system can actually exclude the risk of infection, so it is a question about the probability by which you minimise that risk and many of the systems that we are seeing and reading about -- not particularly England -- still leave many, many gaps and many risks," Baer-Hoffmann said.

Baer-Hoffmann admitted that plenty of players around the world were keen to get back playing despite the potential risks involved, but said FIFPro recommended that players undertake three to four weeks of training before beginning matches again due to the risk of injuries.

In England the Premier League has been suspended since March 13.

The financial consequences of not restarting would be potentially very serious for clubs, although players at the top level in England are in a better position than some of their counterparts around the globe.

Baer-Hoffmann highlighted the case of players in several Latin American countries, including Colombia and Uruguay, as well as in Botswana and Egypt, who are now relying on food packages from their local players' union "because they cannot even provide for their own basic needs and are being stranded in terms of income".