Thousands of fans are returning to Wembley Stadium on Sunday as part of a Government programme to ensure the safe return of live entertainment.
FA Cup semi-final spectators will be part of a large research project looking at how fans and audiences can safely attend events again, with music events to follow in the coming weeks.
Along with the World Snooker Championship, which started on Saturday, the pilots will be part of the UK Government's science-led Events Research Programme (ERP).
It comes after non-essential shops reopened on Monday along with outdoor hospitality, gyms and hair and beauty services.
FA cup semi-final
The FA Cup semi-final between Leicester City and Southampton on Sunday will host an audience of 4,000.
While the snooker at the indoor Sheffield Crucible Theatre will operate at the socially distanced capacity of about 325 for the first few days.
The intention for both Wembley and the snooker is to steadily reduce social distancing and increase capacities over the course of the research programme.
In Sheffield, after the first few days it will move to 50% present capacity and then move towards 100% capacity of around 1,000 over the course of the 17-day tournament.
The FA Cup final at Wembley on May 15 will see 21,000 people in attendance.
Other events, such as those taking place at the Circus Nightclub in Liverpool on April 30, will not have social-distancing measures in place, but will operate at a reduced capacity.
But before attending any of the events, spectators will have to test negative for coronavirus in a lateral flow test (LFT)- supervised where possible - taken in the previous 36 hours.
And after attending the occasion, they will be asked to conduct a PCR coronavirus swab test.
Professor Iain Buchan, executive dean, Institute of Population Health, chairman of public health and clinical informatics, faculty of health and life Sciences, University of Liverpool, explained that only those who consent to taking part in the study will be able to attend.
Explaining the process, he said: "So what will happen? You will see an advert for the event via some media.
"At the Liverpool events we have arranged for people looking at those adverts to immediately go to the site that explains the event research programme, where they will give their consent if they wish to go further, consent will be recorded, people will be informed about what they're likely to be asked.
"And they'll start going through questionnaires online.
"That will give them a token to then book a ticket and part of activating your ticket will then be getting a test within 36 hours before the event.
"People may receive text messages by phone as well, to say 'have you got any symptoms on the day of the event and if so, you shouldn't go'.
"Five days after the event, those who have become part of this research study will be asked to take a swab up their nose at home, and they'll be asked the questions as well that will be triggered probably by text message.
"It will vary between the different events, but this is very much an ethically thought through careful science led programme that we'll be pursuing."
Potential outbreaks ‘likely to be quite rare’
Prof Buchan said many of the events will be safer than mixing happening in other settings, as people will have been tested beforehand, and encouraged to limit their contact with others before and after.
He added that local public health services will receive data very quickly on any potential outbreaks and be able to trace and contain them.
The risk is the equivalent to "about one in several thousand people" and based on the current background rates of infection "that is likely to be quite rare", Prof Buchan explained.
He continued: "The main thing we want to do is make sure that those mechanisms are in place, so if rates do rise, say for example in July, that we have a very, very effective safety net, and we can decide whether or not to go ahead with particular events, vary in the spacing, the choice of venues to licence more of the outdoor venues with lots of fresh air."
Venues participating in the programme will test specific settings to collect evidence and best practice.
The programme will explore how different approaches to social distancing, ventilation and test-on-entry protocols could ease opening and maximise participation in these sectors in the future.
The findings will be used to provide key scientific data and research into how small and large-scale events could safely reopen in line with the road map out of lockdown - particularly step four which is due to commence no earlier than June 21.
As part of the programme, Covid-status certification will also be trialled.