The Scot has come under increasing pressure after a poor run of form, which has seen the Midlands club being dragged into a relegation battle.
However, McLeish has said that the club was battling to beat the drop last year with a stronger squad and he knew that it would be a tough job when he took it on.
"I know the supporters don't want this," said McLeish. "They want Villa to be up in the top six or something. That's Villa's history and heritage. At the moment, it's not realistic. But we want to be there again and everyone has to understand about the way we are steering the finances.
"One thing you certainly cannot do is take this league for granted. You can't come in and say 'the Aston Villa badge means we will be in the top 10'. I looked closely at the squad when we discussed the financial side of things and thought it was going to be a tough job.
"Villa were relegation-threatened last year with a stronger squad. But you obviously think that maybe players will play out of their skin and we'll get a wee bit of luck here and there and we can stay clear the whole season. But I knew there was no guarantees of that."
McLeish suffered relegation from the Premier League last season when in charge of Birmingham City.