The England boss will announce his pre-tournament squad on Tuesday afternoon ahead of friendlies against Bosnia and Herzegovina and Iceland, before it is then whittled down to 26 players for the Euros.
Southgate has decided to name a larger ‘training’ squad due to the absence of a number of players for the first few days of the camp, as well as the question marks hanging over some of his injured stars.
Manchester United and City’s players are unlikely to be involved in the first friendly due to their participation in the FA Cup final on Saturday, while Jude Bellingham will not be released by Real Madrid until after the Champions League final on June 1.
Southgate is expected to use the additional space in his squad to try out some defensive options, with the situation at left-back of particular concern to him.
First-choice full-back Luke Shaw has not played since February and suffered a setback in his recovery recently, while back-up Ben Chilwell has been limited to just 10 minutes of Premier League action since the beginning of March.
Both players will be given the chance to prove their fitness, but Southgate is thought to be leaning towards making Kieran Trippier his first-choice option at left-back.
Even that is something of a risk, with the 33-year-old having made just two brief substitute appearances and one start since recovering from a calf injury.
With the doubts over Shaw and Chilwell, Southgate could also select the likes of Levi Colwill, Ezri Konsa or Joe Gomez who all have the versatility to cover at both centre-back and left-back.
One player who looks set to miss out on a place in the squad is Raheem Sterling, who does not expect to be picked and is facing up to the prospect of missing a first international tournament in 10 years since being picked by Roy Hodgson for the 2014 World Cup as a teenager.
Although he netted in Chelsea’s final match of the season against Bournemouth, players such as Cole Palmer, Anthony Gordon and Jarrod Bowen are all ahead of him in the pecking order.
There are no major concerns over Gordon even though he missed Newcastle’s end-of-season win over Brentford – and their post-season trip to Melbourne – while Bowen only missed West Ham’s trip to the Etihad due to illness.
Marcus Rashford could well make the provisional squad despite a drop in form, while the likes of Jack Grealish, Eberechi Eze and James Maddison are likely vying for one or two spots due to Southgate’s need to bolster the defensive side of his squad.
Eric Dier could make a surprise return after his excellent performances for Bayern Munich, but Jordan Henderson and Kalvin Phillips are thought to have faded out of contention – with Trent Alexander-Arnold now the likeliest midfield partner for Declan Rice.
Harry Kane, meanwhile, should be fit for the tournament despite missing Bayern’s final match with a back issue; the skipper has already returned to England and is working with his long-time doctor to address the injury.
‘Harry is receiving treatment from his personal doctor,’ revealed Bayern boss Thomas Tuchel. ‘He cannot travel. He was already at the limit versus Real Madrid. It was a borderline decision for him to play.
‘He had a complete blockade in his back, it’s got worse and bothers him in everyday movements. There was no chance for him to participate in the game.’
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