The Premier League have remained tight-lipped over the sudden surge in positive coronavirus cases that have been sweeping pre-season training camps since the weekend.
It comes after a total of 14 cases were recorded at just 12 clubs, though Sportsmail understands that the positive tests have been recorded by staff as well as players.
In contrast there were only 30 positive cases from around 35,000 tests carried out during Project Restart so the increase is significant, and is likely to be the result of players and staff travelling more widely during the summer.
Ryan Fredericks (left), Mason Mount (second left) and Declan Rice (right) were recently pictured together on holiday on the Greek island of Mykonos
Tottenham’s Dele Alli (right) met up with Leicester midfielder James Maddison (centre) and Aston Villa captain Jack Grealish (not in picture) on holiday in Ibiza
With more than three weeks remaining before the start of next season on 12 September the positive tests are not expected to disrupt the preparations for the new campaign, but they have provided a warning of the need for clubs to maintain a Covid-secure environment at their stadia and training grounds. The Premier League is expected to test players once a week next season rather than twice a week as they did during the resumption of the last campaign.
The Premier League declined to comment on the issue when contacted by Sportsmail.
Premier League champions Liverpool recorded one positive case this week after embarking on their pre-season trip to Austria but have remained silent on the matter.
Manchester United, City, Chelsea and Wolves are not back yet following their European commitments this month.
As well as Jurgen Klopp’s men, Tottenham, Everton, Southampton, West Ham, Crystal Palace, Leicester, Newcastle, Sheffield United, Brighton and newly promoted Leeds are all back in training.
There is also an anxious wait for United duo Marcus Rashford and Jesse Lingard, who are yet to discover if they will be forced to cut short a holiday in Greece to avoid a two-week quarantine that would cause them to miss the start of pre-season training.
The England and Red Devils duo flew to Greece earlier this week after United’s Europa League quarter-final defeat by Sevilla — despite the probability that returning holidaymakers will be subject to quarantine measures from this weekend.
Rashford and Lingard undertook the trip with the blessing of United, but only after manager Ole Gunnar Solskjaer warned his players that they had to be available for pre-season training on September 1.
West Brom and Burnley will be back on Thursday, while it is not known when Aston Villa are returning to work, though Jack Grealish shared a snap of him on Instagram returning to England from his holiday this week.
Arsenal and Fulham are not back yet following the conclusion of the 2019-20 domestic campaign and their involvement in the FA Cup and play-off finals.
The figures remain unofficial, with the Premier League only expected to begin regularly publishing test results when the season starts on September 12, but Sportsmail understands them to be correct.
Marcus Rashford (left) and Jesse Lingard (right) may be forced to rush home from their holiday in Greece (pictured here abroad on a previous occasion)
Former Leicester team-mates Ben Chilwell and Danny Drinkwater pictured together in Greece
Grealish shared a snap of himself on his way back to England after summer break this week
Chelsea stars (left to right) Christian Pulisic, Tammy Abraham and Fikayo Tomori in Mykonos
Everton goalkeeper Jordan Pickford (left) was also in Mykonos, with partner Megan Davison
Clubs fear that cases could continue to rise after players were pictured flouting social distancing rules to party with rival stars on holiday over the past few weeks.
Tottenham’s Dele Alli was pictured with Leicester playmaker James Maddison in Ibiza along with Aston Villa captain Jack Grealish, while West Ham star Declan Rice holidayed with Chelsea’s Mason Mount on the Greek island of Mykonos and Blues midfielder Danny Drinkwater hung out with Foxes defender Ben Chilwell.
There is no suggestion that these players have tested positive for coronavirus, or that they have contributed to the spread of Covid-19 within Premier League clubs.
Players and staff members were following strict coronavirus guidelines but have since been released by clubs to enjoy time off in the close-season.
Players are understood to be among those who have tested positive, and not all are believed to have been asymptomatic.
There has been a spike in positive coronavirus cases among Premier League players
Tottenham’s Son Heung-min was pictured back in training on Wednesday morning
Southampton’s players being put through their paces after returning to training this week
All top-flight clubs will undergo testing in the next few days, and with more than three weeks to go until next season starts there is not expected to be too much disruption to the opening weekend.
However, it has fired a warning to players and staff to continue with the strict protocols that were in place for the final nine games of last season following the three-month absence of Premier League football during the coronavirus crisis.
All persons testing positive will now have to self-isolate for at least seven days.
Players are expected to be tested once a week when the season gets underway, rather than twice a week as they were from May to July.