Son scored for the third consecutive game at the weekend, a magnificent breakaway goal to confirm all three points in a 3-1 win over Leicester.
Pochettino has not forgotten that incident and was incredulous in his response to Sunday's re-run.
"Do you think that Sonny deserved to be booked?" I think we are such nice people.
He will no doubt be looking to impress after being heavily criticized after last years games against Tottenham.
"It was the same referee but now I don't know how he has measured the situation". Today will be the last time I say this message. Over two games we were the better team against Real Madrid (four points from two group games) who were the eventual winners of the trophy. "We are nice people".
Dortmund are five points clear at the top of the Bundesliga, and Pochettino accepts that his team face a huge challenge in the coming weeks - but has backed them to progress.
Borussia Dortmund will be without their captain and star player Marco Reus for Wednesday's Champions League last-16 first leg against Spurs due to a thigh injury. "It's a massive disadvantage to play with one day less to prepare".
Asked about the huge impact Sancho has made, Pochettino said: "He doesn't surprise me".
Goalkeeper: I don't think there is much debate over who'll start in goal as Hugo Lloris is nearly certain to keep his place between the sticks with Paulo Gazzaniga having to make-do with a place on the bench.
He said: "I really believe that we can win every single game".
He has them well-drilled and they have lost only twice in all competitions...
But Lloris came to Tottenham's rescue, plunging to his right to keep out Vardy's spot-kick.
"That's what I said to Michael". For a young player, we have to find good consistency.
Leicester's positive start to the second half brought a golden opportunity to equalise with their 60th minute penalty.