Manchester City teenager Foden remains with the U21s due to a lack of first-team football at club level.
“I'd probably try to calm Phil's situation because there's a lot of expectation around him," explained Southgate.
“I think that's a huge pressure for a young player potentially. At the moment a lot of his name has been forged with our junior team. That's how he appeared on the scene and we're really happy with his progress.
“His mentality playing with the Under 21s in the last match was great. He needs those matches. He needs that stamina and that game time."