Bent has been the subject of speculation linking him away from Villa despite only making the £18 million switch from Sunderland in January. Young and Stewart Downing - the main creators for Bent during the second half of last season - departed Villa in the summer but McLeish is confident the former Tottenham player will remain.
When asked if he faces a struggle to retain the services of Bent, McLeish said: "I don't think so. I've not heard anything. As far as I'm concerned, he's here for the long run."
He added: "We need him. He's a terrific finisher. Sometimes he only needs one chance. That's the value of someone like Darren Bent. If we can create one or two sniffs (of a goal), then Darren will be in there."
McLeish was resigned to losing Young to United shortly after he replaced Gerard Houllier in June and is not surprised at how quickly the player has made an impact with the Red Devils.
He said: "Ashley is a great player. Reading his story was fascinating about how he was discarded as a youngster and had the determination to make himself a top pro.
"It's a brilliant story that any youngster should read. He's been a real success story. He's a dangerous player and going to United has not affected him.
"He's not fazed by it and he's almost taken up the gauntlet in showing the other United players how good he is."
McLeish added: "Ashley staying here was never going to happen. I knew that from day one after I came here. The club tried very hard but it's difficult when one of the top clubs in the world comes in.
"If there was any chance, I would have tried because you don't want to lose the top players."
Source: PA
Source: PA