Young, who moved from Villa to United in the summer of 2011, has had the accusation of diving levelled at him on several occasions over the last few years, and spoke out about the matter this week.
The 28-year-old England international was unapologetic, saying: "The referees are giving decisions and that is where I think it lies."
And, giving his thoughts on the issue ahead of Villa's home Barclays Premier League clash with United on Sunday, Lambert - appointed the midlands outfit's boss a year after Young's departure - said: "I don't think he actually dives intentionally, trying to throw himself around.
"I don't know Ashley Young at all, but I wouldn't say he is one of these lads who just goes out and tries to dive.
"He tries to do good things on the football pitch and sometimes you get caught - sometimes players move that quick and the slightest nick can take you over, and then it is up to the referee to call it the way he sees it.
"I don't see him as being a diving-type player. Maybe some decisions have been highlighted because the incidents have involved him."
Lambert has also given his backing to Young's manager at United, David Moyes.
The Red Devils, the defending Premier League champions, have so far had a hugely disappointing 2013-14 campaign following Moyes' appointment over the summer, and they are currently ninth in the table, 13 points adrift of leaders Arsenal.
The way things have gone for the Old Trafford club under their new boss has generated plenty of talk of a crisis, but Lambert said: "I think people are getting carried away by where United are in the table.
"They are still a top club with top players.
"Any manager going in there - it doesn't matter who it was, what country they came from, anything - after probably the most successful manager Britain has ever produced (Moyes' predecessor Sir Alex Ferguson) was always going to find that really hard to do.
"So I think the criticism is a bit over the top.
"They have had success for years and years, and when you fall below that really high standard, then people jump on the bandwagon and say they are a spent force. I never really buy into that.
"I'm pretty sure David Moyes will get that job right.
"He is a really good manager and a good guy - I'm convinced he will get that job right.
"He is just in the door. I think some of the criticism has been pretty harsh."
Villa - 11th in the table at present, three points worse off than United - will be without midfielder Fabian Delph for the contest.
Delph is suspended having picked up his fifth yellow card of the season in the 2-0 defeat at Fulham last weekend.
In terms of injuries in his squad, Lambert has reported that centre-back Ron Vlaar is "struggling" with his calf problem, but indicated that full-back Antonio Luna and striker Libor Kozak, recently sidelined by groin and toe complaints respectively, may be available on Sunday.