Drogba rejoined Chelsea last month, signing a one-year deal after his contract with Turkish side Galatasaray expired.
The Ivory Coast international enjoyed a magnificent first stint at Stamford Bridge, winning the Premier League three times, the FA Cup on four occasions and the UEFA Champions League in 2011-12.
A prolific eight-year spell ended with Drogba scoring over 150 goals for the London outfit, but at 36 there are doubts over whether the former Marseille man can reproduce anything close to that sort of form on his return.
Drogba is likely to be the back-up to Spain's Diego Costa - who arrived from Atletico Madrid in July - with Romelu Lukaku, the player long touted as his heir apparent, sold to top-flight rivals Everton.
But Terry remains confident that the move will prove to be a good one for Jose Mourinho's men, and feels Drogba's experience could have a positive impact on Chelsea's younger players.
"Didier's still the same. He's been a nightmare to play against in training. He's still physically strong, sharp and hungry as well," Terry told Chelsea TV.
"It's important Didier is here because he brings that mentality of wanting to win every day and that rubs off on people like [centre-back] Kurt Zouma and the other young players he's playing against."
It has been a transfer window of great change for Chelsea, who - in addition to Drogba and Costa - have recruited Cesc Fabregas and Filipe Luis.
Meanwhile, long-serving players Ashley Cole and Frank Lampard have moved on, with the latter set to play for Manchester City on loan after joining affiliate MLS franchise New York City.
But, while Terry is saddened by the departures of that pair, he feels fans should be excited by the club's future.
"It just doesn't seem right to see them [Cole and Lampard] in different shirts," he added.
"The club are evolving. One day we'll all be gone.
"It's time for these players to continue to keep winning trophies for this club and keep the fans and owner happy.
"If I was a Chelsea fan I'd be impressed from what I have seen so far from Diego, Cesc, Filipe and all the boys that have come in like Kurt as well."
