"I've really enjoyed playing and training for John. Probably more so, if I'm honest, in the past couple of years than at any other stage of my Wales career.
"I've got an awful lot to thank John Toshack for. He made me captain of my country, the biggest honour any footballer can have, and I've relished the responsibility of helping to bring on the younger players.
"But I don't believe I've been playing as well as I could have done for Wales, probably because of the amount of football I've had this season.
"Maybe I haven't been as fresh as I should have been. It will suit the three parties, myself, Manchester United and Wales for me to stand aside.
"It will help Wales because the current group of experienced players, who are not my age group, can come to the fore more, dominate games, take on more responsibility on the pitch in the way they perhaps wouldn't have done were I still playing.
"Have no doubts, this Wales team have a very good future ahead of them. There is definitely enough quality in the squad, I see that day in, day out when I train with them.
"It's just a question of transferring that ability into matches in terms of results achieved.
"But, given time, whether two years, three years, or whatever, Wales could well qualify for a major finals.
"The current group of players currently in their mid-20s will be more experienced and battle-hardened by then. And the current crop of youngsters will have gained the experience they need of regular international football.
"I'm quite confident about the future. It only takes one good result for Wales to suddenly go off on a really good run ... and, fingers crossed, that result could even come against the Czech Republic on Saturday."
Asked how Toshack reacted when told of Giggs' decision to quit, the Welsh captain said, "I think he was half expecting it.
"Credit to John, he didn't try to change my thoughts. He listened to what I had to say and wished me the very best for the future.
"In return, I want to see the team under him keep improving ... and improving and improving and improving.
"They will, too. John's had to deal with an awful lot of retirements from the senior players since taking over as manager and mine is just another one of those.
"But, having brought down the average age of the team, John knows that the side will get better and better.
"I will never achieve my dream of playing in a major finals with Wales, but there are many players in the current squad who may well get there one day.
"But I can't grumble about what's happened to me. I've been fortunate to achieve an awful lot at club level and I have set my sights on achieving more still."
Asked when he had made his decision to call it a day with Wales, Giggs said, "As recently as five weeks ago, I was fully intending to carry on playing.
"But I believe this is the right time to go. It's the end of the season and there are a few months before the next games, away to Bulgaria in August and at home to Germany in September.
"That gives plenty of time for everyone to get used to me not being involved any more and for people to focus only on the future.
"I appreciate some people will raise eyebrows about me quitting half-way through a qualifying campaign.
"But better to go at this point, for the reasons I have outlined, than make a decision like this when Wales' games are coming thick and fast in the autumn."
Asked for his high points with Wales, Giggs cited three.
"My debut in Germany back in 1991. My full debut against Belgium in Cardiff two years afterwards. And, without doubt, being made captain of my country," he said.
"I would like to thank John Toshack for giving me that opportunity. Hopefully, in my last game on Saturday, I can lead the team to victory."
Toshack paid tribute to his departing skipper, saying it had been a privilege and a pleasure to have him as his lieutenant on the pitch.
"Ryan came to see me last week, in the build-up to the friendly against New Zealand, and I could see he was a little bit disturbed," said Toshack.
"I had an idea what might be coming, and it duly did.
"I would like to say it has been a privilege to have Ryan as my captain. He has always set a terrific example to the young players in the squad.
"We shall certainly miss him. I think we are talking about a very special person here.
"He has played on the international scene for 16 years, which is an incredible period of time.
"And he has done it under quite a bit of pressure, probably more so when he plays for Wales than when he does for his club.
"I would like to wish him the very best and put on record my thanks about just how much he has helped me.
"And I would also say this. Players often wonder what to do when they finish playing football.
"I always tell them things have only just started for them at that point ... and that's something I emphasise to Ryan, too."