All things being equal, Stuart Lancaster would not have made a single change to his England side for this weekend's intriguing Calcutta Cup set-to with Scotland at Twickenham: even the most meddlesome selectors tend to leave well alone after runaway victories over New Zealand. But Lancaster lost two of his top-of-the-bill acts just recently, so he had no choice but to tinker.
The first of the absentees – Manu Tuilagi, aka the "human bowling ball" – should be back in business by the mid-point of the Six Nations, by which time Billy Twelvetrees of Gloucester may have muddied the midfield waters with some big performances at inside centre. The second, the loose-head prop Alex Corbisiero, will not be available for Test duty until the end of the season, if then. The best-case scenario has him playing for London Irish some time in March. The worst-case scenario is too grim to contemplate.
Tom Wood, the red-rose enforcer who won the man-of-the-match plaudits against the All Blacks before Christmas and will start on the blind-side flank against the Scots, knows how he feels. Corbisiero's knee condition, so chronic that the front-rower has just undergone a third bout of surgery since last summer, may never clear up completely, just as the foot injury that threatened Wood's career still needs careful management. Wood may be back in the swing of things at international level after spending much of 2012 on the sidelines, but he must train differently from everyone else in the squad if he is to keep himself fit.
"I had a good chat with Alex during the training camp in Leeds," said the Northampton back-rower. "He's a bit concerned, which is understandable. He doesn't want to disappear off the radar, especially at a time like this when the big games are around and the pressure is on. But I also think he's confident he'll be back. Sometimes, you just react badly to a rehabilitation programme. After this latest operation, things could be different for him. He just needs to be patient.
"As for me, I feel fit and ready to go. But even though I want to do all the training, the medics are being very cautious with me and are good at holding me back. Perhaps that was what I needed in the first place, although I hope it won't always be like this. At least there are ways of letting off steam if I can't train with the squad. I spend a lot of time in the gym, hammering the weights and the exercise bike." If Scotland were once renowned for a fast and loose approach to back-row selection, they have gone for size this time round by picking two very solid citizens, Alasdair Strokosch and Kelly Brown, on the flanks. It is almost as if they made their choice with Wood in mind. If so, the Englishman is more than happy to meet the visitors' expectations.
"They've named a big, physical unit, and as we are expecting wet conditions on Saturday, it will be real battle up front," he said. "We'll need some brawlers – people who will get on the floor, down and dirty, and put their heads where it hurts. We're happy with that. Scotland will come out full of fire and put pressure on us, so it's up to us to deal with it, to govern ourselves.
"The challenge for this England team is to reproduce the intensity we generated against the All Blacks regardless of opposition or occasion. That's our benchmark now, the place we have to get back to each time we play. Just because we beat New Zealand by running in some tries, it doesn't mean it will automatically happen again. Consistency is ingrained in the All Black culture and, like them, we have to realise that no one game is more important than another."
With Twelvetrees preparing for his international debut – Brad Barritt, the first-choice No 12 in recent games, will move out one position to make way for the newcomer – the England midfielders have much to prove. The pack, however, is more rooted, with Joe Marler of Harlequins expected to be confirmed as Corbisiero's replacement.
Meanwhile, the much talked about Leicester teenager George Ford has spoken for the first time about his impending departure from Leicester – almost certainly for Bath, where his father, Mike, the former England defence coach, now works. "Playing a full 80 minutes is what I need to be doing," said the 19-year-old England Saxons outside-half, who will feature against Scotland's second string in Newcastle on Friday night. "It was one of the toughest decisions I've had to make and I didn't take it lightly, but the more you play, the better you get. It's difficult when you're on the bench, coming on for 10 or 20 minutes each game."