Mourinho is under pressure at United following a tumultuous pre-season and last week's shock 3-2 Premier League defeat at Brighton.
The 55-year-old boss, who replaced Louis van Gaal in 2016, is reportedly at odds with executive vice-chairman Ed Woodward after United failed to meet Mourinho's transfer demands before the deadline, with Fred, Diogo Dalot and Lee Grant the only new faces.
"For every single manager who is younger than him, he was an inspiration," Spurs manager Pochettino said. "For everyone.
"Of course. I took a lot of things from him. So many things. He is an unbelievable manager.
"I am younger than him, of course. The circumstances that happen with me, that happen with other managers, they will happen, it is up and down.
"He is an inspirational manager for a manager like me. I have a very good relationship with Mou from when I was a manager of Espanyol and I have full respect for him and the club."
Pochettino's Tottenham will be looking to make it three wins from three matches to open the Premier League season, while United are desperate to avoid back-to-back defeats.