The Villa boss has always been aware of Ireland's ability to unlock opposing defences and he impressed against Arsenal and Chelsea playing behind the main striker.
But McLeish believes adding other traits such as aggression and tackling to his game have helped Ireland to become more popular with supporters.
McLeish was even booed for substituting Ireland during the home defeat against Swansea on Monday.
McLeish said: "We haven't seen the best of Stevie but there has been a little bit of a glimpse of that in the last couple of games and long may that continue.
"He has now set the benchmark and has got to keep playing at that level because he definitely brings something to the party.
"If Stevie can deliver those sort of performances, he can open doors at the back. He is a good footballer.
"But it also helps if he puts himself around. The Villa fans applauded him when he got stuck in against Arsenal.
"That side of the game is something the fans adore players doing.
"We are trying to help Stevie to master that side of his game as well and he is doing that well."
McLeish insists his decision to substitute Ireland against Swansea was to avoid the risk of injury.
He said: "I can understand the fans doing that (booing). Stevie was tired and came out of nowhere to play half a game against Arsenal, a full one against Chelsea and then 70 minutes in the Swansea game.
"The one thing I don't want to do, especially with a small squad experience-wise, is to lose someone like Ireland to injury especially when he is playing well."
McLeish has pledged to field a full-strength side against Rovers, who this week sacked manager Paul Buckle, and urged his players to show their mettle against the League Two strugglers.
He said: "I know it was a long time ago when the club last won the cup (1957) but we certainly are aware of all the giant-killing feats.
"We don't want to have any room for complacency at the weekend. It's a potential banana skin.
"I can remember all my own exploits, winning the cup five times as a player with Aberdeen, and going into similar ties.
"The opposition will be saying 'let's see if they fancy it' and they get in your face. You have to roll your sleeves up and show your mettle.
"We are live on TV as well and I'm sure there will be some people loving to see some cup upsets this season but we've got to make sure we are not one of them.
"We need a professional job, no room for complacency, and we will play as strong a team as possible."
McLeish remains confident striker Robbie Keane will complete his loan move from the Los Angeles Galaxy after the weekend and believes he will be keen to make a big impression at Villa.
McLeish said: "We are hoping Robbie will be here sometime next week after the FA Cup game.
"He has certainly got the experience, the character. He is a guy who is going to be playing in a huge tournament (Euro 2012) at the end of the season.
"I'm sure Robbie Keane will not want to let his standards drop at this stage of his career. If anything, we should have a massively motivated boy."
