The 48-year-old highlighted Young's tumble at Old Trafford against Aston Villa last season that won the Red Devils a crucial penalty.
"I remember very well last year when Young was swimming in the box," Mancini told The Sun.
"Four or five times in the last 10 games and no-one said anything. Fergie is clever for this."
|7/2||Ashley Young is 7/2 with Paddy Power to score at anytime in the Manchester derby on Sunday afternoon|
The Scot had earlier questioned the amount of penalties the defending champions have been awarded at the Etihad Stadium.
"If we got that number of penalty kicks, there'd be an inquiry in the House of Commons," The 70-year-old commented.
Since August 2010, City have been awarded 20 Premier League spot kicks at home, while United have only recieved 13.