“As a team, we have to recognise that we’re in a good moment and the team are playing well,” he said. “There’s a squad of players, any of whom are more than comfortable coming into the side and playing well when they’re coming into the team.
“But also those moments can be dangerous because if we get any sense of complacency then we’re going into a game where we’ll be really challenged and this is a big opportunity for us.
“We can really take a positive step towards the World Cup if we win in Warsaw, so it’s a high level of motivation, but also guarding against any feeling that we were better than we are.
“We’re having a good run of results because we’re working hard for each other, because without the ball we’re very disciplined and that sets the tone for our game.
“It’s an opportunity, no more no less. We know that to go away from home and win is not easy, not straightforward. Poland also have high motivation, to be able to top the group they probably have to win the game, so it’s a game for everybody to look forward to.”
Southgate rang the changes against Andorra, but he is expected to recall his key players on Wednesday.
“You could argue over what is our strongest team,” he said.
“The team that played in Hungary, obviously we were able to rest those guys after the game, but there are still huge competition for places in this group and it’s not so straightforward just to say we won that game and this team will go again and give the same level of performance.
“The challenge of the game in Poland will be different, the rhythm of the game can be different, the problems you get on the night can be different. We can’t just drift into the match, we’ve got to make sure that our levels of concentration are really high.”
Predicted England team: (4-2-3-1) Pickford; Walker, Stones, Maguire, Shaw; Rice, Phillips; Sterling, Mount, Grealish; Kane.
England squad: Sam Johnstone, Jordan Pickford, Nick Pope, Trent Alexander-Arnold, Conor Coady, Reece James, Harry Maguire, Luke Shaw, John Stones, Kieran Tripper, Kyle Walker, Jude Bellingham, Jordan Henderson, Jesse Lingard, Mason Mount, Kalvin Phillips, Declan Rice, Patrick Bamford, Jack Grealish, Harry Kane, Bukayo Saka, Jadon Sancho, Raheem Sterling.
Wednesday, 7.45pm BST, ITV
Venue: Stadion Narodowy, Warsaw
Referee: Daniel Siebert (GER)