Dier has had a mixed start to life at White Hart Lane following his switch from Sporting Lisbon, scoring the winner on his debut against West Ham before struggling to make the right-back berth his own.
Kyle Naughton has often been preferred in the position, with Dier recently pulling out of the England Under-21 squad due to an apparent desire to focus on training as a centre-back rather than a full-back.
While Dier denied the suggestions, stating he merely wanted to focus on settling in at Spurs as opposed to featuring in friendlies against Portugal and France, Pochettino wants to see the 20-year-old become more adaptable.
With the defender likely to be required against Hull City on Sunday due to the absences of Naughton and Kyle Walker, Pochettino also explained the situation involving Dier's withdrawal.
"It was Eric's own decision to speak with [Under-21 manager] Gareth [Southgate]. He never consulted with us," he said.
"Before he arrived here Eric played a lot of games at right back, centre back and midfield.
"His future will be better if he improves in different positions. This gives more possibility to play in the starting XI.
"He needs to improve."
