Wales legend Gareth Edwards has admitted he is ''stunned'' by Mike Ruddock's departure as national coach.
Ruddock rocked the rugby world on Tuesday when he called time on his 21-month reign as Wales boss.
During 20 Tests in charge, Ruddock led Wales to the 2005 RBS 6 Nations Championship and a Grand Slam, while notable victories were also achieved over Australia and Argentina.
Australian Scott Johnson has taken charge for the remainder of this season's RBS 6 Nations campaign, and is clear favourite to become Ruddock's long-term successor despite being strongly linked with a role alongside new Wallabies head coach John Connolly.
Edwards though, believes Ruddock has left a considerable void.
"I am almost gasping with astonishment," said the former Wales captain and scrum-half.
"The immediate concern from the rugby point of view is that even though there are a number of people who are capable of taking the mantle and who will have been very much part of the Welsh set-up, Mike was the central figure.
"He was the dynamo that made all the other parts work. This is certainly a blow to the Welsh set-up - his contribution has been absolutely immense.
"My reaction is one of huge surprise, and in taking the few words that have been given to us about his reasons, you have to respect them and wish him all the best," Edwards told the Western Mail.
Wales resume their RBS 6 Nations programme against Ireland in Dublin on February 26, still holding a realistic chance of retaining the title despite a 47-13 defeat to England during the tournament's opening weekend.
With England facing a clash against France in Paris next month, it appears unlikely that any team will go through the competition unbeaten, and Wales put themselves back on track through a 28-18 victory over Scotland last Sunday.
One of Johnson's first tasks will be to decide on a possible recall for centre Gavin Henson, who missed Wales' opening two RBS 6 Nations games while he completed a 51-day ban imposed after elbowing Leicester prop Alex Moreno during a European Cup match in December.
Henson is expected to begin his comeback for the Ospreys against Celtic League opponents Borders on Friday night.
England flanker James Haskell insists he will be pushing as hard as possible to be back from a toe injury in time to make his case for a spot in Eddie Jones' side looking to defend their RBS 6 Nations title next year.