Bentley said: "There's no doubt the gaffer has what it takes to manage Manchester United. Of course he has, it's not even an argument. He would not be fazed by big players and big personalities. He could handle them all and take them on if necessary, no problem.
"He's done a great job at Blackburn and - with all the backing you get at United - I'm sure he would be a success. I think it would be a natural progression for him. He's been there and done it and commands respect the moment he walks into a room.
"The day I signed for Blackburn I knew he would be good for me.
"All the best managers are there when you need them but they never get too close to the point where they become your mate. They treat their players well and encourage them when it's needed but also give them a kick up the backside if necessary.
"I wouldn't want the manager to be my mate, he has to have that distance and a bit of a ruthless streak to make the team successful. Our gaffer has all of that. He has a way about him where you want to give the maximum for him because he encourages you to work with the ball and express yourself.
"You are scared not to do well because he has done everything to get the best from you. He's incredibly passionate about his football, just like he was as a player and I know he will be desperate to beat United.
"We all want to win, of course - but it won't be more than him."