This midweek's round of international friendly fixtures constitutes a last chance for many players to force their way into the reckoning ahead of the World Cup in Brazil in June and July.
Wedged into a busy period in the club season, 99 days before the World Cup itself begins, it is the only international date before most coaches announce their squads for the finals in May.
Teenage full-back Luke Shaw has been excellent in the Premier League for Southampton, but the friendly against Denmark at Wembley will be his one opportunity before the summer to show England manager Roy Hodgson he is ready for international football.
Shaw was called up for the first time as Hodgson named a 30-man squad for the game, although he has insisted that he has "no eyes on the World Cup" at his tender age.
"It's not a definitive squad," Hodgson said last week.
"The fact someone is on this list does not say he will be going or be one of the seven standby players because I reserve the right to change my mind on those subjects."
England are preparing for the start of their World Cup campaign against Italy in Manaus, so they will be keeping a keen eye on the Azzurri's friendly clash with Spain in Madrid.
- Costa set for Spain debut -
The game at Atletico Madrid's Vicente Calderon stadium is a repeat of the Euro 2012 final, which La Roja won 4-0 in Kiev, and it is also set to see Atletico's Brazilian-born striker Diego Costa make his Spain debut.
Costa, 25, has scored 21 times in La Liga this season and Spain have had to battle with the Brazilian Confederation to get him on board.
"His is a singular case, he was born in Brazil but he became a footballer in Spain and has shown in his club that he deserves to come into the squad. That is why we have called him up," said coach Vicente del Bosque, who notably left David Villa, Fernando Torres and Juan Mata off a list that continues to evolve ahead of their World Cup defence.
Spain's opening World Cup test will be against the team they beat in the 2010 final the Netherlands in Salvador, and the Dutch continue their preparations with a heavyweight friendly of their own, away to France.
Dutch coach Louis van Gaal, who looks set to be replaced by Guus Hiddink after the summer, will give chances to youngsters such as Davy Klaassen of Ajax for the game and there are some new faces in the France squad too, such as Real Sociedad forward Antoine Griezmann, scorer of 15 goals in La Liga this season.
"I can't recreate the same context but we will need to maintain the same spirit and motivation," said France coach Didier Deschamps of what is his team's first match since the dramatic play-off win against Ukraine in November that took them to the World Cup.
- Loew admits Germany concerns -
World Cup hosts Brazil cross the Atlantic for a meeting with South Africa in Johannesburg, where coach Luiz Felipe Scolari expects a tough test against a side who beat Spain in November, and Germany entertain Chile in Stuttgart with coach Joachim Loew admitting to concerns about the form and fitness of his bigger names.
"On paper, we have a top team, but the reality at the moment is a bit different," said Loew.
"Several players have been injured for months, while others have struggled with a lack of rhythm or form."
Chile's pedigree cannot be doubted, and Jorge Sampaoli's team beat England 2-0 on their last trip to Europe in November.
The South Americans are preparing to face Spain and the Netherlands in their World Cup group, as well as Australia, who take on Ecuador at Millwall's ground in London.
Elsewhere, Romania host Argentina in Bucharest, while the United States face Ukraine in a match that will be held in Cyprus due to the current political tension in Kiev.