O'Neill has gradually improved the fortunes of Villa during his four years at the helm.
This season they have reached the final of the Carling Cup, the semi-finals of the FA Cup and are battling for a Champions League spot by securing a top four place in the Premier League.
But that has not stopped speculation that O'Neill may quit in the summer because club owner Randy Lerner may be gearing up to tighten the club's purse strings.
And the former Celtic boss, who has made it clear he wants to remain at Villa, has been upset at times with the reaction of a small section of supporters.
McLeish said: "I don't know the ins and outs of Villa Park. I don't know if Martin is under pressure but I know sometimes that expectation levels get out of hand and maybe people are asking too much in certain situations.
"I'd swap with him any day in terms of what Villa have achieved this season. He is a great manager with a proven track record. I don't think he needs to be disillusioned about anything.
"Is he a victim of his own success? Yes, I suppose in a way he is and sometimes you can achieve more than is expected and than all of a sudden the expectation levels grow out of proposition.
"As managers, we've seen it all before in recent years where one or two managers come fifth or sixth and then they are out the next season because they can't get into the Champions League.
"It is a little bit of the nature of it these days, the knee-jerk and blame culture we live in."
McLeish has performed wonders at City this season but insists they are still a long way short of being at the same level as Villa although he knows on any given day his players could produce an upset.
He said: "There is a huge disparity still between us and Villa. We've still got a long way to go to catch up with a club like Villa?
"We have come a long way in the two years I've been here. We are still not at the level of Aston Villa but on a given day we can produce a performance and that's what we will be looking to do at Villa Park."
McLeish added: "People say the fans would love for us to end the Champions League hopes of Villa. We are not looking at it like that.
"We are looking for our own reasons, bragging rights from the derby, the fact Villa beat us at St. Andrew's.
"We would like to think we could go to Villa Park to win the game but we know we will have to play at our very best, give one of the best performance-wise this season, to get something from Villa.
"They are on a run of 10 points from 12, Martin will be delighted their form, they've got match-winners and that was the difference between the teams at St. Andrew's.
"We matched them on that day and they had just that wee but of quality in the last third we are still striving for."