Once it became obvious Toshack would be leaving his job following last week's defeat to Montenegro, Giggs immediately shot to the top of the Welsh FA's hit-list.
The 36-year-old was an obvious choice among those who remember how well another former United player, Mark Hughes, did when he found himself in a similar situation.
However, it was always felt Giggs would prefer to concentrate on his playing career.
And Ferguson has confirmed that is exactly the way it is going to be.
"I spoke to him. It will not happen," said Ferguson.
According to Ferguson, the possibility of Giggs combining management with a high-profile playing career is just not realistic.
"It is impossible to do both," he said.
Stories in recent days have appeared where Giggs talks positively about launching a management career and he is in the process of collecting the relevant qualifications required for him to take such a post.
However, Ferguson views the Welshman as a major component of his squad.
Although the present campaign has only just begun, the United chief is already looking ahead 12 months.
And he simply does not feel Giggs would stand the best chance of extending his career still further by taking on draining international commitments with Wales.
"We have to be selfish here," he said.
"I am not even prepared to negotiate on this matter.
"At his age, Ryan needs to use all his energy and concentration to be here.
"It is a big season for him. It is maybe his second last, it may be his last. We want it to be the second last.
"The best way for that to happen is for him to concentrate on being here."