The 33-year-old, captain of his country, will lead them into battle for one last time against the Czech Republic on Saturday at the Millennium Stadium in his home city of Cardiff.
Already the phone lines are buzzing and the attendance could well be more than doubled from the previously expected 25,000, to see Wales' best player of the modern era play his last game for his country before retirement.
Only John Charles is considered to have been a better player than Giggs in Wales' football history, and the Cardiff-born legend admits it will be an emotional farewell.
But with one final year on his Old Trafford contract, it is clear that Giggs now wants one last swansong before his United career comes to an end.
He said: "This decision will now keep me fresher throughout the season.
"The last two months of the season I hardly trained, it was game, recovery, game.
"Now I won't be away on international duty and will be able to train and work at being ready for the next club game.
"There are always young players coming through at United, you dare not underperform or go through the motions.
"You must perform at the highest level each time you go on the pitch. Not just one in three games, you must do it every time.
"There is no compassion at a club like United and I wouldn't expect any.
"We want to win things and everyone has to be at their best. I have one season left and I would love to win the Champions League again."
He added: "We went so close this season, and it is a massive motivation to win it.
"I have said I want to win it again, it is the only competition I have only won the once, and everyone at United feels that.
"It is my motivation now. I may have another season at United after this next one, I don't know what will happen then. So I want to make the most of this season coming up.
"I have a year left on my United contract, we will just have to see what happens next - but hopefully this will benefit me long term.
"I will see how next season goes. I have felt okay this season and aim now to feel even better next."
The demands of the tough opening to each season - with Champions League and international football running side-by-side - have forced Giggs to quit his Wales career.
He said: "It is difficult to handle the opening months of a season. You play internationals, Premier League, Champions League, week-in, week-out.
"That is very demanding. Sometimes you come back from an international and everything overlaps. That is difficult and you have to be at your best for every game.
"And that is hard when you do not have the chance to rest and train properly between matches.
"I have learned to manage my injuries these days, but you are constantly recovering. I aim to be fresh and stronger."
He added: "I'm 33, the Premiership does take it out of me. Every season the pressure on teams and individuals gets tougher, and that will keep on happening.
"It is such a great league to play in and win, and it's always tougher. Chelsea and Arsenal have raised the bar and now United are there to be shot at.
"You can't stand still as an individual and as a team, you cannot stand still. And if I want to be involved I need to manage things differently.
"Every season I try to look for that extra two or three per cent, in terms of diet and treatment. I'm always looking to improve and that won't stop, be it ice baths or massages. I hope that next season with the extra rest I will get will give me that edge."
Giggs hopes he has left Wales with time to plan for their future. he said: "I felt it was the right time for me and for Wales as well.
"After this game they will have plenty of time to prepare for the qualifiers and friendlies next season.
"I did not really want to be still do it(for Wales)in that time when we have two international games virtually every month at the beginning of the season.
"My motivation has not dropped, definitely not. If being captain of your country does not motivate you, nothing will.
"I've enjoyed playing and training with Wales more so over these last couple years than at any time even if it has not been as successful as I'd have hoped."
Giggs, who will be replaced as captain by Craig Bellamy after Saturday's match, said of his decision to go: "It helps myself, getting breaks during the season and it will help Manchester United because I will be playing less football.
"But also it will help Wales because I do not feel I have been performing as well as I could.
"Maybe it is because of the amount of football I have been playing, I don't know. But everyone will benefit from this, club, country and myself."