"Playing for United, you have got to have the temperament, personality and be right off the field as well," he explained. "To be a top player for United, you have got to have more than ability. It's about drive, professionalism and you must want it more than anything in the world. Hopefully, we're going to get some players through pretty soon."
Butt is also sure that Sir Alex Ferguson will maintain a healthy level of interest in the younger players at the club despite moving into retirement.
"I think it's very important not to forget that he will still have an impact on the club," insisted the ex-England international. "The manager will be knocking on his door asking for his opinion and he will still be looking at the younger set-up, maybe even more so now he has the time to do that.
"He's still got a massive part to play and nobody should underestimate that. The way he speaks about the new manager means he's very confident in him. We've got to give him all the opportunity we can to become the great manager that Sir Alex was."