The Three Lions head coach picked an initial squad of 25 for the games, with four of those players available only for Monday’s Euro qualifier in Swansea due to age restrictions for Toulon.
And with a number of players here for the first time with the Under-21s under Southgate, there has been a feeling of something of a mini reunion around the group.
Wales U21s v England U21s
UEFA European U21 Championship
7.30pm, Monday 19 May 2014
Liberty Stadium, Swansea City
Live on Sky Sports
"A lot of the new lads have played together and come through the system at U17 and U19s level," said Southgate.
"That helps players to settle in and there's very few boys that are here for the first time and don't know anybody else.
"What we're looking at during the first few days is players arriving with different workloads from the recent weeks.
"Some players finished 10 days ago, some finished a week ago and some played at the weekend or have been away for a few days.
"So we need to get them together, get an idea of where they are physically and all of our focus at the moment is on the game with Wales and then we can look forward to Toulon after that."
Despite a number of the squad Southgate has called upon for the campaign so far being unavailable through injury or play-off involvement with their clubs, he is pleased to be able to cast his eye over some new players.
The squad were back in training at St. George's Park on Thursday
And he is happy with the standard of player he has been able to call up for the games, which represent a chance for many of them to stake a claim for the next campaign.
"I think that you find with whatever tournament we’ve been to, you often miss a certain number of players and you can find new players who just need the opportunity," added Southgate, whose side will face the likes of Brazil, Colombia, Qatar and South Korea in Toulon.
"When you talk about youth development at club level, you always talk about players getting the opportunity and it’s no different here.
"Until you’re able to get players in and working in this environment and see the challenge of training against each other, you start to see the level they can reach."
You can watch the full interview with Gareth in the media player above.
England fans hoping to see the Under-21s in action against Wales at the Liberty Stadium in Swansea can still purchase tickets for the game for just £5 for adults and £2 for concessions. Call 0844 8156665 for details.