Liverpool manager Jurgen Klopp is optimistic about the chances of completing the Premier League season as the champions-elect returned to training in small groups on Wednesday.

Klopp's side were just two wins away from ending a 30-year wait to win the title when the English top-flight was shutdown more than two months ago due to the coronavirus pandemic.

Six positive cases of COVID-19 were detected in the Premier League's first round of 748 tests of players and staff ahead of a return to socially distanced training this week.

At the start of the outbreak, Klopp accepted football should be suspended if it would help save even one life.

But the German believes it is now safe for players to return to phase one of training.

"I always said we don't want to rush anything, but I don't think it is rushed. It is for the first step, for this kind of social distancing training," Klopp told the Liverpool website.

Newcastle defender Danny Rose (right) says Premier League players are being treated like "lab rats"
Newcastle defender Danny Rose (right) says Premier League players are being treated like "lab rats" AFP / Justin TALLIS

"It was a long time, it is still ongoing, but the development is going with everything in the right direction and that helps.

"That football is closer to coming back I think is really a good sign for people as well."

Sheffield United manager Chris Wilder is also heartened that just 0.8 percent of the tests carried out by the Premier League resulted in positive cases.

"A lot of people have been tested and the signs are encouraging," said Wilder, whose side are in contention to qualify for European competition for the first time in their history.

Germany's Bundesliga resumed its season behind closed doors last weekend, becoming the first major league to return to action.

The Premier League's target of restarting on June 12 has been called into question by players' concern for their welfare, both from the threat of the virus and injuries with little preparation time after such a long layoff.

However, Wilder does not believe fitness should be an issue as players have been able to maintain their conditioning during the lockdown.

Back to work: Jurgen Klopp arrives at Liverpool's training ground on Wednesday
Back to work: Jurgen Klopp arrives at Liverpool's training ground on Wednesday AFP / Paul ELLIS

"They weren't off to Dubai or Vegas eating and drinking whatever they want," Wilder added.

"They've got a professionalism about them and my players are in absolutely brilliant condition. We've tested them right the way through. They've got individual programmes. They didn't know when this was going to kick-start and they had to be ready."

Newcastle and England defender Danny Rose though is angry at the restart plans, arguing that players are being treated like "guinea pigs or lab rats".

"I could be potentially risking my health for people's entertainment and that's not something I want to be involved in, if I'm honest," said Rose on the Lockdown Tactics podcast.

Watford captain Troy Deeney says he will not return to training this week over fears he could pass the virus onto his five-month-old son.

Deeney is reportedly one of a number of Watford players who will not report to the club's training ground after three of the six positive cases in the Premier League were registered at the club.

"Of those three positive tests, one is a player and two are members of staff," Watford said in a statement.

Burnley confirmed assistant manager Ian Woan, who is asymptomatic, aas another case with two more from one other club yet to be revealed.

Meanwhile, Tottenham have launched another investigation into one of their players after defender Serge Aurier appeared to flout social-distancing rules for a third time.

The Ivorian posted an Instagram photo on Tuesday showing off his new haircut and tagged the barber in his post.

Hairdressers are closed in Britain in line with the government's rules on social distancing.

Spurs have previously had to remind Tanguy Ndombele, Davinson Sanchez, Ryan Sessegnon and Moussa Sissoko of their responsibilities after they were pictured in breach of social distancing guidelines.

Manager Jose Mourinho also admitted his wrongdoing in arranging a one-on-one training session with Ndombele in April.