The delayed tournament kicks off in Rome on Friday with a total of 24 teams playing across 11 cities.
Euro 2020 is approaching the business end of things as with progress to the knockouts and elimination from the tournament at stake.
On Monday, Denmark, Finland and Russia all have a chance to join Belgium in the next round from Group B.
The Danes have lost both their matches so far at Euro 2020 and have played most of the time without Christian Eriksen after he collapsed on the field against Finland in the opener.
But Denmark can still get enough points to advance from B if they beat Russia in Copenhagen and Finland lose to the world’s top-ranked side Belgium in St Petersburg.
A crowd of up to 25,000 will cheer Denmark at the Parken Stadium as they seek an unlikely qualification for the last-16.
“We’re prepared to run out at the Parken and have a magical night… it’s like our Euro is starting right now,” Denmark coach Kasper Hjulmand said on Sunday.
“We’re not done. We had a difficult start and we’re going to start over now. We’re ready to get through the group and play more games.”
A win by two goals or more would be enough if Finland lose, as would any one-goal success other than 1-0.
“It would mean a lot… after everything that we’ve been through I think we deserve it,” said captain Simon Kjaer.
Russia will be out to spoil the home team’s day, though, knowing just a point would be enough to finish second if Belgium win.
Roberto Martinez’s Belgians are not yet guaranteed a top-two finish, but a draw would see them through as group winners.
— UEFA EURO 2020 (@EURO2020) June 21, 2021
Meanwhile, in Group C, Andriy Shevchenko’s Ukraine are just a point away from making the knockout stage for the first time after successive group exits in 2012 and 2016.
Ukraine and Austria will face each other in Bucharest, knowing a draw is likely to be enough for both to advance.
Both sides have three points so a winner would go through, with the loser having an anxious wait to see if they were among the four best third-placed teams.
But a draw would seem mutually convenient as it would put Ukraine through in second-place on goals scored and leave Austria third with four points and a goal difference of zero – very likely enough to reach the last-16 too.
The winners will face Group A winners Italy at Wembley in the next round.
The Netherlands have already won Group C and their visitors North Macedonia are out.