The 47-year-old adjusted his system during City's 3-1 defeat to Ajax, a result which all but ended their hopes of advancing in the Champions League.
After the game, Micah Richards admitted that he along with his team-mates found it difficult to adjust to playing with three centre-backs.
Mancini hit back at those comments saying if any of his players can't adjust to the system, they don't deserve to play.
“If you’re a top player, it’s not important what system you use,” the Italian told The Mirror.
“If you don’t understand, you’re not a top player and you can’t play for a top team.
“I don’t want to speak about Micah, because I don’t think it’s important what he said after the game.
|MANCINI DEFENDS TACTICAL SWITCH
|9/1||Man City are 9/1 with Paddy Power to beat Swansea 3-1
“He was only answering one question. But we work hard every day at tactical situations and all the players know the system.
“When we were 2-1 down to Ajax, we didn’t concede [again] because we changed the system - we conceded a third goal because of a stupid mistake in a one against one.
"We changed because Ajax were only playing with one striker. If you want to change the game, you have to change something on the pitch. So when we wanted to be more offensive, we had to leave only three defenders back.”Although City favoured a back four for the majority of last season, Mancini says he employed three centre-backs numerous times and all to great effect.
“With this system, we beat Chelsea 3-2 in the Community Shield,” said Mancini. “Last season we recovered - with one less player - against Manchester United, from 3-0 to 3-2 and almost got a draw, using this system.
“So with this system, every time we have changed the result.
“Maybe Micah doesn’t know this because it was the first game for him because he was out for two-and-a-half months.
“Probably he worked on it less than other players, but maybe next time we play this system, Micah can stay on the bench."