The Government's decision to put in place a 14-day self-isolation period for people coming into the UK could have far-reaching ramifications for sporting events this summer, including the British Grand Prix.
At least initially, there is no exemption for elite sportsmen for the quarantine mandate which will come into force on June 8 and be reviewed every three weeks.
The PA news agency understands discussions will continue about whether this year's races can go ahead behind closed doors in July and Silverstone's managing director Stuart Pringle remains optimistic.
Ten races have already been postponed or cancelled because of the coronavirus pandemic but Pringle hopes Formula One can prove its staff will be able to enter the country safely without the need for quarantine.
"I am very clear that the importance of the industry is understood by Government," he told Sky Sports. "I remain very optimistic that they will find a way.
"I'm very, very conscious that it's extremely complicated drafting these things and working up against ever-moving deadlines – it's not a task I'd wish to undertake.
"So I remain optimistic that a sensible and pragmatic solution, which puts the onus on the sport quite rightly to come up with the right solution, can be found."
The F1 season is due to start in Austria in early July before heading to the UK, where seven of the sport's 10 teams are based, and Silverstone has said an agreement in principle is in place for the Northamptonshire circuit to stage two races.
"It's a very complex sport to get going because it's a global championship with a huge logistical tail, so Formula One does need to know that it can set off on its global travel and be able to come in and out of its home base," Pringle added.
"Our industry has stopped – stopped full stop – and we need to get it back going again. There are a lot of people's livelihoods associated with this.
"It's not so much about a race, it's much more about getting back to business. This is about getting an industry back to work."
The new quarantine rules could have an impact on the Champions League, which has been on hiatus since March 23 with half the last-16 ties still to be completed and two English teams still left in the competition.
UEFA will not comment on the Government's update until it knows what is happening with its European competitions, although the situation could become clearer at an executive committee meeting on June 17.
The results from the first round of Covid-19 testing among Championship players is set to be published on Sunday.
Second-tier clubs are set to start small group training from Monday amid the crisis, after players underwent initial tests on Thursday and Friday.
The English Football League will publish how many tests were conducted, and the number of positive tests, if any. League One and Two players have not been tested and therefore cannot return to training on Monday.
Watford defender Christian Kabasele believes the potential Premier League return date of June 12 is "impossible" and that action should not resume until later that month.
Phase one of small group training began this week after testing got under way. Defender Adrian Mariappa and two members of Watford's staff returned positive Covid-19 tests ahead of the resumption of training, while on Friday boss Nigel Pearson revealed two more of his squad are in self-isolation after members of their family tested positive.
Kabasele told the Counter Attack podcast: "We speak about June 12. I think it is impossible because it would be less than three weeks training after a long period without doing anything. It's a risk for us."
UK Athletics has confirmed it is investigating claims that senior members of its coaching staff oversaw a training session where social-distancing protocols were broken.
The Times alleged a video had shown some coaches flouting Government guidelines at a training session said to be near Loughborough.
UKA would not comment on the content on the video but told the PA news agency: "We are aware of the footage and are currently investigating the circumstances around it."
UKA added no athletes are currently being investigated as a result of this footage.
Ascot has unveiled the running order for this year's Royal meeting, with six extra races added to the fixture along with changes to the timing of some of the feature events.
The shutdown has forced a number of switches to be made to the showpiece meeting, which is scheduled to kick off on June 16 and will be held behind closed doors.
Seven races are planned on the first four days, with eight on the final day highlighted by the St James's Palace and Coronation Stakes.
The Burghley Horse Trials, due to take place from September 1-5, were cancelled and will not go ahead for the first time since the events' inception in 1961.
