Fully fit again after months of anguish and self-doubt, he is by no means out of the woods. As any right-thinking loose forward will confirm - and Rodber earned his corn as a No 8 or blind-side flanker for a full decade - there are few prospects more purgatorial than a career switch to the second row, where the shoulders always ache, the ears mutate instantly into cauliflowers and the nostrils are perpetually irritated by their proximity to the rear ends of a prop on one side and a hooker on the other. Forget sport as enjoyment. This is sport as torture. Only General Pinochet could love it. And yet, Rodber's switch from loose to tight may be the final making of him.
If Captain Tim (a captain in the Green Howards as well as the captain of Northampton) can emulate Fabien Pelous, of France, and South Africa's Andre Venter by successfully adapting to life in the darkened recesses of scrum, ruck and maul, he will give the English heavy mob the kind of footballing dimension Clive Woodward spends his nights dreaming about. What is more, he will rid himself of his reputation as an arch-flatterer of the deceptive variety.
Anyone judging Rodber exclusively on the basis of 80 golden minutes against the Springboks in Pretoria in June 1994 would unhesitatingly rank him among the great loose forwards of this or any other era. But 80 minutes do not add up to a career, however often you recall the shuddering, muscular forays that rocked Loftus Versfeld to its very foundations. For all his physical gifts - 6ft 6in, 17 stones, brick hard and seriously rapid - Rodber has been more out than in these last four years or so. To the extent, indeed, that senior southern hemisphere coaches have been known to question his "ticker".
"I've been criticised most often in the past for not putting in the full 80 minutes, for disappearing during games," agreed the 29-year-old Yorkshireman this week. "I don't necessarily think all that criticism is justified; as a loose forward, you tend to pick and choose your moments, to give it 100 per cent in short bursts in order to maximise your impact. But we'll see about the 80-minute thing at Twickenham, won't we? Second-row forwards have to grind out the effort over much longer periods. It's 90 per cent dog from first whistle to last. I understand what is expected of me and I'm confident of delivering.
"It's a big change, of course; not just a change in technique but a change in mindset, in the whole way I think about the game. But the bridge is not quite as uncrossable as some people assume. More and more, coaches are moving away from the tight-five back-row theory and looking to go four and four: that is to say, boost the loose-forward capacity by playing a second row who can contribute a flanker's tackle count and play a bit of ball as well as perform the traditional duties in the scrum, line-out and restart areas. As a No 8, my tackle count used to be up around the dozen mark. As a second row at Northampton, I've been matching that figure."
So far, so hunky-dory. But tractoring up and down the channels at Franklins Gardens is a very different proposition to spending a Test match in the close company of John Anthony Eales of Queensland, Australia, and the Rugby Heaven XV. Rodber has yet to start an international in his new position; his recent part-time engagements at Huddersfield were against the Dutch, whose locks had more in common with Julie Andrews than Mark Andrews, and the Italians, against whom he was not a conspicuous success. Eales, on the other hand, is the finest second row in the world. An interesting one, eh?
"He's a great player, Eales," Rodber acknowledged. "He's right up there with the best of all time. But if you can't bring yourself to relish a challenge like this, why play at all? I've been an international player since 1992, I've got 34 England caps and I've played two Tests for the Lions against the Springboks that must be among the biggest games anyone has ever experienced.
"Basically, I've been around a fair while and picked up some know-how along the way. I've got good people around me, too: Martin Johnson, Jason Leonard, real big-leaguers. I think we'll make a go of it.
"This is precisely the opportunity I've been looking for because there have been times in my career when I've wondered whether it might all be slipping away. Back in 1996, Jack Rowell cut me to ribbons and told me I wasn't anywhere near as good as I thought I was and, even though Ian McGeechan picked me for the Lions tour the following summer, that run of injuries prevented me building on what I'd achieved in South Africa. The worst spell was earlier this year, when I mangled my knee ligaments just before the Cup semi-final. That was a real low and when you've been down there, you learn to grab every new chance with both hands.
"The good thing about this England management is their communication. Even though I couldn't tour down south in the summer, Clive stayed in touch, kept talking to me, kept reminding me of the things he wanted me to do. I trained hard, moved into the second row at club level and got myself noticed. When I got on as a replacement against Holland in the first of the World Cup qualifiers, it was like winning a first cap all over again."
Compared with Eales, who is fast closing in on Willie John McBride as the most-capped lock in rugby history, Rodber is indeed a novice. But he is a novice with a past as well as a future. If England's great under- achiever brings back memories of Pretoria '94 this afternoon, Eales will at least know he has been in a game.