A comfortable second half saw the hosts take back control of the tie which produced a positive outcome for Southgate's men with a Marcus Rashford goal deciding the game.
"So numerous lads were playing their first 45 minutes of the season", said the England manager.
While both sides will feel they could've been ahead at the break, it was Switzerland's Yann Sommer who was the busier of the two goalkeepers.
Switzerland were soon gifted a chance to settle into the game, though, as Jack Butland's attempts to play out from the back nearly backfired twice in quick succession - the second of which saw James Tarkowski robbed of the ball and Xherdan Shaqiri subsequently fire a low strike against the outside of the post when he should have done better.
England got the new season back on track with their first win of the campaign. A combination of the two meant we got a good response in the second half.
The home truths exchanged in the dressing room at half-time resulted in a far shaper England performance in the second-half. "Today they were harsh on themselves".
She's the most inspiring person I know
She is also the second Japanese player to reach a Grand Slam singles final after Kei Nishikori, who lost in the final of the U.S. In fact she closed it out with a service victor that bounced wildly off the frame of Keys's racquet.
Calling Butland into a couple of saves in the first half, Rodríguez was making sure he was always an option, and was continuously involved in the Swiss' attractive style of play.
'It's important they have a view, they are intelligent football players, they should have a view of what's going on.
"We talked a bit after the World Cup about the demands of the modern player".
The game was also a reminder of just how unbearable the England band are.
England proved far too strong for the Swedes before falling short against Croatia in the last four, but it is Switzerland who have so far bounced back from their World Cup disappointment the stronger.
"We were very keen that he had the opportunity, we were determined to give him some match minutes", said Southgate.
"It is easy for them to be harsh on themselves but Danny has only has had one match this season and we are suffering a physical situation on the back of the World Cup for so numerous players".