Frank arrived at Brentford in 2016, became head coach two years later and took them to promotion from the Championship in 2021. The Dane left the club in June to replace Ange Postecoglou at Spurs.
"Of course, it's a little more special for me because I face Brentford, where I was for nine years," Frank told reporters on Thursday ahead of Saturday's game.
"Almost a quarter of my life there. I had a fantastic time there, and I enjoyed every second of it.
"A lot of people I'll see on Saturday who I haven't seen for a long time, I used to see them every day, more or less, so that will be special."
Given his obvious affection for Brentford and his history at the club, Frank was asked if he would celebrate if Spurs scored on Saturday.
"Yeah, I will. Everyone knows the respect I have for Brentford, the fans, everyone before kick-off, after the final whistle," he replied.
"In the 90 minutes, it's all about one thing: do what we can to win the game."
After a promising start to the season, Spurs are without a win in their last five league games, losing three, and of their five wins this campaign, their only home victory came back in August on the opening day.
Brentford, meanwhile, are having difficulties on the road, losing six of their seven away games.
"It will be nice timing for us to get the three points on Saturday," Frank said.
"There's only one way to do that: put a good performance in there. Work on the things we are constantly working on.
"Constantly make it sharper, quicker. Not direct, but more penetration when we need to have that. Play with intensity, come out brave. I'm looking forward to the game."
Many expected Brentford to struggle this season after they replaced Frank with an inexperienced manager in Keith Andrews, along with the departure of several key players, but they are level on 19 points with Spurs in the standings.
"I think it's a big credit to Brentford to be brave enough to promote from within, but also to have built something over time," Frank said.
"It's definitely not about me, it's about what we together built there, that consistency, stability and high performance level at this level.
"So that culture, knowing who we are, what we want to be, that was easier to continue with appointing Keith, and I think he's done a remarkable job. It is never easy to step up to your first head coach role."