The Liverpool and Wales record goalscorer feels his country will visit Hampden for their World Cup qualifier a week on Friday with more talented players than Scotland.
Rush is employed by the Football Association of Wales as their elite performance director and he feels their work off the pitch as well as on has helped the likes of Gareth Bale, Aaron Ramsey and Joe Allen play for some of England's top clubs in their teens and early 20s.
Rush said: "For the last five years we have been changing things for kids from 14 years old.
"We have been teaching them what to do when they are 14 and not when they are 16 or 17.
"A lot of 13 and 14-year-olds think they can just go on the field and play football. They don't realise the preparation, the mentality that is needed, the rest they have got to have, and what they have got to eat and drink.
"We have been doing that so, when they are 16 and they go to clubs, they are ready for it, it's not a shock to the system.
"For me it's no coincidence when we see young players like Aaron Ramsey and Gareth Bale coming into the team when they are 17 years old because they are ready for it."
Wales visit Glasgow a point above bottom place Scotland in Group A following their 2-1 victory in Cardiff in October.
Rush said: "I think Wales have got the better players, the more skilful.
"Scotland will work hard as a team but Wales have the better individuals.
"It's going to be a close game because a draw is no use to either team."
Rush was in Glasgow on Wednesday promoting ESPN's upcoming football coverage, which includes Scotland's World Cup clash in Serbia on March 26, along with Joe Jordan.
Jordan helped break Welsh hearts in 1977 when his handball led to a controversial penalty for Scotland during a 2-0 win at Anfield that secured their place in the World Cup finals.
"I was in the Kop that day as a kid and I was surrounded by Scotsmen then as well," Rush said.
"It was a big disappointment. People talk about the handball but what I remember most is Alan Rough made a great save from John Toshack."