The Crystal Palace centre-back, 23, is expected to start alongside John Stones for their Euro 2024 opener against Serbia on Sunday.
Harry Maguire missed out on the tournament with injury and his 63-cap experience could be a big loss for Gareth Southgate.
But Cahill believes Guehi is ready to show his worth – after getting the No6 shirt ahead of Ezri Konsa and Lewis Dunk.
The ex-Chelsea ace, who played at three major tournaments for England, told SunSport: “No Maguire is a massive blow for the country.
“He’s experienced in a position we haven’t really got much experience at the moment.
“Every England career starts from somewhere. The opportunity arises when sometimes something unfortunate happens to others.
“I see a lot of responsibility on John Stones’ shoulders and it will be a new partnership.
“I’d go with Guehi.
“Gareth has relied on him a little bit. I get the feeling that Gareth’s confident with him.
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“Every time he’s played, he’s been good. He’s had a good season at the Palace.
“I think he is a real leader.
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“As a manager, you go off, obviously, the ability, who’s fit and ready to go but also, who’s got a personality and can manage these situations?
“The likes of Kyle Walker and John Stones are used to these environments and will manage that situation.
“It would be new for Marc. But I think he’ll be able to handle that.”
Cahill also believes Arsenal pair Bukayo Saka and Panini ambassador Declan Rice could be the difference makers for the Three Lions in Germany.
The duo will be desperate to put their Premier League disappointment behind them to fire their country to Euros glory – three years on from heartache against Italy at Wembley.
Cahill added: “There’s an expectation level of England now with an exciting and experienced squad.
“I fancy them, certainly as one of the favourites.
“Declan Rice will be vital. He’s one of the most important players in this team.
“He’s one of the reasons why Arsenal competed very strongly this season.
“I would say this as a centre-back but he plays such an important position on the pitch, screening in front.
“Saka is somebody who could unlock teams.
“When you see the game against Iceland, sometimes you’re going to come up against teams that maybe take the lead and then sit back and camp in.
“Somebody as direct as him could have a real impact in games. He’d be the guy that you can turn to to unlock these sort of tight games.”
- The England 2024 Tournament Edition Official Sticker Collection is out now and available in all good retailers. This Sunday, Panini will be sending out its one-of-a-kind England taxi onto the streets of London to celebrate the start of England’s campaign.