Last season he helped Wasps secure the league title with fly-half performances of maturity and class without having a sniff of an England cap. In the summer, he toured Argentina but despite the absence of more than an entire team of Englishmen on Lions' duty, he was still kept waiting. Finally, after Mike Catt had been summoned to South Africa, King made his belated international debut as a replacement for the last half-hour of the second Test, a 33-13 defeat in Buenos Aires.
"It all happened quite suddenly, with Jack Rowell tapping me on the shoulder and saying: 'Get out there'. I was off the bench like a shot. I thought I did quite well and I scored a try. It wasn't brilliant - I got the ball 10 yards out and ran over."
So far, those 30 minutes are all the 22-year-old has to show at the highest level for the regal talents which made him a priority signing for Wasps and earned him the Young Player of the Year award in 1996.
This season, it seemed King's coronation was nigh. He started brightly enough in Wasps' impressive early Heineken Cup displays and word was that he had moved ahead of Catt and Paul Grayson in the pecking order of English No 10s.
Then gremlins struck again. He tore a cartilage in his right knee against Saracens six weeks ago and needed arthroscopy. It was touch and go whether he would be fit in time for the Southern Hemisphere orgy which began a fortnight ago against Australia.
But Clive Woodward, Rowell's successor as England coach, had faith in King and selected Catt outside him at centre. His comeback match against Brive in a Heineken Cup quarter-final the week before went well - "despite a few bumps, although you expect that" - but the injury flared up in training a few days later and, once again, King found himself sidelined. Four caps in as many weeks against the best teams in the world had gone begging.
A lesser man in such circumstances, surely, might have pretended all was well with the injured knee. Frustrated though he felt, King has more sense than that. "You can't go into an important game with an injury like that. I'd only have let myself down and my team-mates. And if I'd played badly I might not have been picked again.
"After I pulled out, Clive said, 'Hang around with us until Saturday. You're very much part of the squad.' But I haven't been with them since they dispersed after the Australia match. I've been having physiotherapy and training at the club, and I'm hoping to be back for Wasps' league game against Harlequins on 13 December.
"If I don't get back soon, though, I'll get even more frustrated. Being picked for England and not being able to play was a terrible experience. My form was good before the injury so it was frustrating that it came when it did. In Argentina, a lot of people were away with the Lions so it was particularly important for me to be picked for the Australia match when everybody was available."
King has watched the current series of internationals with mixed feelings. "Obviously I want to be back in the team and if my replacement has a brilliant game it will be more difficult to get my place back. But I also want the team to win because I'm part of it." Watching from a distance, King was impressed by England's improved performance against the All Blacks. "I think I'd have learned more by playing than watching, but the New Zealand game was very encouraging. To have played in these games against the top sides in the world would have been the best experience of my life. Sure, rugby doesn't get any tougher but sometimes it brings the best out of you.
"Playing four internationals on the trot is a bit like being on tour. The guys will only have three or four days off during the month, but the experience will help when the squad goes to New Zealand next summer. At this level it comes down to confidence, feeling you can cope with playing against the best players in the world.
"December will be a crucial month. I have to prove my fitness and form then if I'm to get into contention for the Five Nations' Championship. But you can't go into important club matches thinking about the England team."
The injury has given King the opportunity to catch up with his business studies degree course, but his mind is understandably elsewhere. Come England's meeting with France in Paris on 7 February, the only words he will want to read are the headline which adds up to the Republican's ultimate nightmare: "King in at No 10."Reuse content