Pochettino guided Spurs to the 2019 Champions League final and turned them into Premier League title contenders as they finished in the top four for four straight seasons before he was fired after a five-year stay in north London.
Chelsea, who appointed Pochettino in May last year, are ninth in the league standings with five matches remaining. Spurs are fifth with 60 points, seven behind fourth-placed Aston Villa, who have played two more games.
"It was special when we played there (when Chelsea played at the Tottenham Hotspur Stadium in November). It was my first time since leaving the club, but now it is a different time," Pochettino told reporters on Wednesday.
"It will be emotional coming up against people who I worked with for a long period. I can't hide my emotion for the club. I think it is going to be emotional because facing a former team, where the history was good, you remember that.
"But I have said before - across the 90 minutes we want to win and Tottenham are going to come here to try and win. It will be a good game."
Chelsea handed Spurs a 4-1 defeat in the reverse fixture in November, in which the hosts were reduced to nine men, to end their unbeaten start to the season.
Thursday's game will mark Pochettino's 400th game as a manager in England. Pochettino was also in charge of Southampton from 2013-14.
"Amazing, a dream come true...," the Argentine said.
"Tottenham was amazing also because the challenge was to create a team that could challenge and compete with top sides.
"Now, arriving at Chelsea, it is an amazing club with an amazing history. It is in the process of building an exciting project that needs time and that is maybe the most challenging period."
Defenders Axel Disasi and Thiago Silva have been added to Chelsea's lengthy injury list, which includes midfielder Enzo Fernandez, left-back Ben Chilwell and right-back Malo Gusto, among several others.