The midfield duo have earned England call-ups on the back of their impressive performances, but Dier insists they must keep their feet on the ground.
The youngster arrived at White Hart Lane from MK Dons in the summer, and has made a big impression, with him now a regular in the Spurs midfield.
A big part of that has been the partnership he has formed with Dier in the heart of the side, with their impressive performances earning both men England call-ups.
And Alli has thanked Dier for helping him to settle at White Hart Lane and play to his potential.
“I’m delighted for Eric that he’s won his first call-up,” Alli told the club’s official website.
“Since I’ve arrived at Spurs he’s been like a big brother to me, so I’m thrilled to be able to work with him in the international set-up. He’s a great guy, he’s really looked after me at Spurs and hopefully we can play together for England.”
Dier knows all about the pressures and struggles of being a young player starring in a Premier League first-team.
He joined Spurs at the beginning of last season, and had to adapt to being used in various defensive roles in his debut campaign.
This year has seen him move into midfield and flourish, with his performances making many forget that he is only 21 years old.
The performances he and Alli have put in have earned rave reviews, and Dier insists that they must keep their feet on the ground and ward against complacency.
“We joke about it, but it’s his first season at the top level and I know how tough that can be,” added Dier.
“Dele’s obviously a young lad so I try to help him out when I can – I’m not sure I’ve got a lot of experience to help him, but I try! We take the mickey out of each other sometimes, but we both have to keep our feet on the ground.”