So when Leicester play Bath at Welford Road in the conclusive match of this season's Courage Clubs' Championship, there will be more at stake for Back than First Division points. With Jack Rowell, the England manager, watching, there are brownie points to be won as well.
Bath have given Steve Ojomoh, who is essentially a No 8, contentious preference over Andy Robinson at open-side flanker and this means that Back, instead of the familiar duel with a breakaway of his own ilk, must tackle a man four inches taller and two stones heavier than his 5-10 and 13-12.
Not only that but the entire Bath back row is made up of big ones whom international managements these days tend to presume will beat less big ones. "I'm pleased Andy isn't playing; I'm glad I've been given the opportunity to play against this big back row," Back said.
"It's happened often enough before that I've had big back rows against me and things have gone well, but Jack isn't going to base his selection in South Africa on one game so it won't be the be-all and end-all. Having said that, I'm in the England squad, not the team, so it's obvious I have to take any chance I can to show what I can do."
The debate will go on between Back's speed and flair, the superb creativity of his handling and support play, and the sheer physical presence of such as Ojomoh or Bath's No 8, Ben Clarke, who holds down the open-side position for England.
Clarke can make mistakes and everyone either forgives or forgets. Yet everyone remembers that Adrian Richter drove through Back's tackle to score a try when the Springboks played England B in 1992; then there was the build-up to the decisive try by Wasps in the cup semi-final just a fortnight ago when Buster White more or less ran straight over Back's would-be tackle.
There is a balance to be struck, though, and the great imponderable about England even after a Grand Slam season is how their back-row behemoths will act on South African going. "England have stuck with more or less the same team for the last six games and have won them all, so they're bound to start the World Cup with that team, with a big back row," Back said. "I'm not under the slightest illusion. They have to fail, or things go quite wrong, for me to get an opportunity.
"But I'm there as part of a squad and I want the squad to do well. In the nicest possible way, I intend to put pressure on to keep the back row on their toes. Whoever they pick, if I can give them any help I will do so. Of course it will be difficult going out there but I'm determined to add as much value to the squad as I can."
This will come as music to Rowell's ears, as will the six-day-a-week training regime Back is about to adopt. By facing Bath, he reaches the England-imposed limit of two of the concluding four league matches and, relieved to have made the World Cup squad, even this most fanatical of fitness fanatics intends to reach a new peak of physical perfection in South Africa.
Relieved rather than rapturous, that is. After England A had played, and honourably lost to, Natal in Durban last month Back was convinced he would not be chosen. Conditioned by previous failures to win selectorial favour and above all by the brevity of his England career when he did make it - two caps last season when he was 25 - he says he had never felt so low.
"I knew the game in Durban was a key game, because it's well-documented that I should excel on hard grounds and in those conditions," he said. "I certainly felt I had played well enough but I have felt that way so many times before and not made it, so this time I was preparing myself for the worst. It was a defence mechanism.
"No one had ever said anything to make me feel I wouldn't be included but there was a lot of speculation at the time, and although I tried to keep away from it, it was a topic of conversation wherever I went. When the party was named I was in bed with flu and I can tell you it was the greatest medicine I could possibly have had."
This, then, has put Back in his most positive frame of mind since being excluded from England's last visit to South Africa, the 1994 tour. Indeed, his inclusion this time demonstrates that he should have gone last time, and he concedes that the effect of that crushing disappointment seriously affected him when the new season began.
"That omission hit me very hard and after being left out of the tour of South Africa I trained like a madman over the summer," he said. "I overtrained and, through basic fatigue really, made myself ill. As a result I struggled for the first few months of this season. I tried to train hard and harder."
So imagine how he would have felt had he been left out again now. "It has been bandied about that I would have retired but that isn't the case; I enjoy the game too much," he said. "But I perhaps would not have continued to devote my whole life. Fortunately it wasn't the case and I will still give my 10 hours of training each week to rugby."
Those 10 weekly hours will henceforth be aimed at turning him into the fastest forward England could imagine, Back having had enough of bulking himself up in order - vainly - to try to compete directly with the likes of today's Bath antagonists and England World Cup comrades, Ojomoh and Clarke.
"I'm not going to be selected on size; if I'm going to be selected it will be for other abilities. So I've gone back a bit from the "body-building". What I'm working on is my own strengths: speed and speed-endurance. I'm talking about pure speed and acceleration off the mark, reaching top speed time and time again with shorter recovery periods. Sprint, sprint and sprint again." With a World Cup to win, the race is only just beginning.Reuse content