Thacker, who is in charge of Leicester Grammar School, and Oakham School’s director of rugby Smith, were teammates at Welford Road.
Now they are passing on their experience to the next generation of rugby players and preparing to face each other in the fourth round of the prestigious competition.
Thacker, a hooker, made 47 appearances for Tigers from 1988-1993, while flanker Smith played 331 games from 1977-1991 and captained and coached the club.
Thacker said: “Smith was the finest captain I played under. It’s always good to have the chance for a catch-up with him.
“There is a rivalry between the schools and between the players but not between myself and Smithy. We will just be happy to see a nice a game of rugby.”
Leicester Grammar School are enjoying their best run in the competition in eight years since a side that included Luke Abraham, the former Tigers flanker, reached the last 32.
Thacker said: “There are no outstanding individuals in this team. They are just a good team who work hard for each other.
“No one stands out head and shoulders above the rest. They are a solid squad who want to play for each other."
