Southgate spoke about adding younger players to his squad, as his side prepares for the UEFA Nations League competition.
"We're three games into a new season and we looked through a lot of different players over the last couple of years and decided that because of the way we want to play and the type of players we want to work with that there are some guys that didn't fit that model," Southgate said to theWatford Observer.
"And so now we're into a fresh cycle of probably not going back to players that have been in before and that we've had a good look at.
"So the next group that we start to look at are probably coming through our younger age groups.
"There's a couple of others that are still young, that still have room for growth – the (Nathaniel) Chalobahs, Will Hughes, Ross Barkleys - but I don't want to bring them in now, three days into the camp."