Both players are part of Roy Hodgson's 26-man provisional England squad for Euro 2016 and Rashford is set to get his first senior international run-out in Friday's warm-up match against Australia.
It is only three months since the 18-year-old Manchester United striker made his senior club debut and there has been plenty of talk about the chances of him continuing his rapid ascent with inclusion in Hodgson's final group of 23.
Rashford has netted eight times in 18 appearances in all competitions for United.
And Tottenham utility man Dier said of the teenager on Wednesday: "It's a bit of a fairytale isn't it?
"It is brilliant for English football and for him, and I'm really happy for him that he is here with us.
"Hopefully we can look after him, there won't be too much pressure on him and he can do what he has been doing for his club here with us."
Regarding the amount of young players like himself and Rashford in Hodgson's squad, Dier, 22, added: "I think maybe Harry (Kane, the 22-year-old Tottenham and England striker who made his senior international bow in March 2015) opened the door for people like Marcus this season.
"It is brilliant that if you are good enough, you are old enough and I think he fully deserves all the credit he has been getting.
"It has been an unbelievable few months for him."
Dier admits he has had a "crazy" time of it of late himself.
The 2015-16 season has seen the ex-Sporting Lisbon man - a relative unknown when he joined Tottenham in the summer of 2014 - excel in the holding central midfield position he switched to from defence as an exciting Spurs outfit pushed eventual champions Leicester all the way in the Barclays Premier League title race.
Meanwhile, he made his senior England debut in November and has gone on to emerge as a key man for his country - although it seems he is not entirely comfortable with that label.
Dier, speaking at the Etihad Campus in Manchester where England trained on Wednesday ahead of the Australia game, said with a smile: "I wouldn't call myself a key member of the team!
"But it has been a crazy 12 months for me - if you told me 12 months ago I would be sitting in this position right now, I'd think you were crazy.
"It has been a great 12 months and I'm really enjoying every minute of it.
"I'm looking forward to what is ahead and hopefully I can repay the manager's faith he has put in me and keep improving."
While he loves the midfield role he has been given, Dier has also stressed he is more than willing to drop into the heart of defence if Hodgson - who has three centre-halves in the 26 in Chris Smalling, Gary Cahill and John Stones - requires.
"I have enjoyed it (the midfield role) very much from when I started playing there for my club until now," Dier said.
"It has given me great things in football this season with Tottenham and England.
"But, of course, I'm happy to play anywhere the manager wants me to play and ready to do that
I don't see that as a problem."
Source : PA
Source: PA