The two sides played out a 0-0 draw behind closed doors in the UEFA Nations League, with Sancho winning his first cap as a second-half substitute.
Aged just 18, Sancho has lit up the Bundesliga this season, providing eight assists and scoring one goal in 10 appearances in all competitions.
And Tottenham midfielder Dier believes the teenager can become a key part of Gareth Southgate's set-up in the future.
"I think he was fantastic when he came on," Dier told Sky Sports.
"He was direct and technically he's very gifted. Hopefully he can be a big part of England in the future if he keeps working hard."
Captain Harry Kane echoed his Spurs club-mate's sentiments, having been impressed by the impact the winger made.
"He's great," the Three Lions forward added.
"Big congrats to him for his debut. I thought he came on and made an impact as well.
"He's been great in training and he has just got to keep working hard and playing games and I'm sure he will have a very bright future."