Germany booked themselves in as England's next opponents by coming from behind twice to scrape a 2-2 draw with Hungary and finish second in Group F.
The Germans have been playing a 3-4-3 formation at Euro 2020 and their wing-backs, Joshua Kimmich and Robin Gosens, ran riot in a 4-2 victory over Portugal last weekend.
England used a back-three and wing-backs in their run to the 2018 World Cup semi-finals and Mourinho believes Three Lions boss Gareth Southgate could revert to that style with Harry Maguire, John Stones and Tyrone Mings in defence when they play Germany next week.
A lot was made about including Maguire in the squad given his injury problems before the tournament began. However, he came through the game against the Czechs with flying colours in his first start.
"I keep saying when you have an option to take 26 players, you have to risk, gamble and take an injured player if the player deserves that," Mourinho explained to talkSPORT after the win over the Czechs on Tuesday night.
"Maguire is one of those players. He was confident, he was stable, he was intelligent [against the Czech Republic].
"He read the game well and he has a good partnership with Stones.
"Mings is doing a fantastic job, you could feel he was happy to come in for 10 or 15 minutes, he is a team player.
"I wouldn't be surprised if the next game is against Germany, the way they play with Havertz, Muller and Gnabry, three defenders and two wings backs - I wouldn't be surprised if England went with three at the back: Stones, Maguire and Mings."
And the fact the game is in London offers England an advantage and a win could propel them to the promised land.
"The next one is the one because it will be against a top team," he continued. "Yes, an advantage because of Wembley, but pressure because it will be a big opponent.
"If they go to the quarter-finals, this match could be the one which pushes them all the way."