England has the most inexperienced squad left in the tournament and should, in theory, be hitting its peak at the European Championships in 2020 or the World Cup in Qatar in 2022, but Southgate believes it would be a mistake to adopt that thinking, Reuters reported.
“Although our team will be better in two years with more life experience, maybe the cards on injuries and things won’t fall as kindly and we won’t get this opportunity again,” he told ITV News.
“It’s dangerous if I start to get carried away, but I’m proud of the way we’re playing,” he said.
Should England get past a resilient Swedish side, it will face the winner of the quarterfinal between host Russia and Croatia in the last four.
The dramatic penalty shootout win over Colombia in the last 16 caused wild celebration back in England and the team has captured the country’s imagination.
While his players have been watching social media videos of the celebrations, Southgate said he is delighted to see the impact of his team.
“It’s a huge privilege to be able to send everybody to work happy, to be able to make a difference to people lives,” he said.
“Football can bring connection through a country and I’m delighted we are exciting people, bringing enjoyment and we want to keep it going,” added Southgate, who himself has risen to prominence during the tournament with his calm style earning plaudits.
England will probably be without its backup striker Jamie Vardy for Saturday's game, due to a groin strain, although injury worries for Ashley Young and Kyle Walker appear not to be so serious.
But Southgate said it can be tricky to rely on players for honest opinions about their fitness at this stage of the tournament.
“The lads would always be prepared to risk injury for these games, but that can’t be to the detriment of the performance level. When it gets to these games, they’re not always as honest as they might be about how fit they are. So you’ve got to have a racehorse trainer’s eye at times to really try and sort that out,” he said.