Spurs manager Jose Mourinho afterwards insisted it was nothing against the 24-year-old and said there is "no story" over Dele's future, despite reports linking him with Real Madrid as part of the negotiations to bring Gareth Bale back to north London.
Dier was on the receiving end of a similar Mourinho decision last season when he was hooked after half an hour of a Champions League tie against Olympiacos, with Spurs trailing 2-0, and has backed his friend to recover.
"He took me off after 30 minutes, it's even worse!" Dier said. "Dele is fine. We're big boys. Football is not a nice world, it is about results and performances.
"Dele is not the first person to be taken off at half-time and I don't think it's the first time he has been taken off at half-time and it won't be the last it is the same for all of us.
"That is a thing that can happen in football. If you want to be a big player it's how you react and move forward with it and knowing Dele and his mentality he will take it in that way and work even harder and try and push on from there."
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