Off the field they are close and on it their fates seemed forever entwined but England flanker Pat Sanderson is determined not to emulate his brother Alex in at least one respect - a career-ending back injury.
The Worcester captain has been forced out of the first three matches of this year's RBS Six Nations after being sidelined with a second back problem.
Sanderson's appearance in last Friday's win over Bristol was his first start since December 17 and he looked as though he was proving his fitness ahead of Saturday's tournament opener with Wales until he was taken off at half-time.
At the time it was claimed he had suffered a cut head but 24 hours later it transpired the 28-year-old had instead succumbed to yet another back condition.
But Sanderson yesterday refuted the suggestion that his troubles were anything like as serious as those that forced his younger brother into retirement last November.
"It's not the same thing that my brother had - he was far worse," he said. "I mentioned it on Saturday when I found out what I had done and he was a bit gutted for me.
"But I am used to getting injured. In the position I play there are lots of collisions and they are getting bigger. You have got to accept that it's going to happen and if you don't then don't play rugby."
Sanderson denied the injury was a recurrence of the one that kept him out of five consecutive Worcester matches and voiced his irritation at the interruption to his burgeoning claims on an England shirt.
"It is pretty similar to the last one I had, just in a slightly different place," he said. "It's massively frustrating but I should be used to it by now, I've been doing it ten years."
The dynamic openside described the six-week prognosis as 'fairly realistic' but refused to pencil in a return for the France game on March 12.
"I can't be thinking that far down the line, I just have to concentrate on what I need to do tomorrow to get fit again," he said.
If Sanderson was to sit down and contemplate the games he could be playing in, it might drive him to distraction.
England take on Grand Slam champions Wales this weekend, then travel to Rome and Edinburgh and will expect to have won all three matches going into the showdown in Paris.
He dare not think about it. "I'm terrible when I'm injured, it frustrates me to death," he said. "I have had a few in the past but no matter how many you get it never makes it any easier to deal with. Especially with the way things are going at the moment I am desperate to be involved."
Meanwhile, Sanderson's Sixways team mates Tony Windo and Phil Murphy have agreed to remain at Worcester beyond this season.
The evergreen Windo, who arrived at Worcester July 1999, has signed a one-year extension to his current contract that will see the 36-year old prop at Sixways until June 2007 - an amazing eight years after being thought too old by Gloucester.
Windo has been an integral part of the Worcester team and not only captained the 2003-4 promotion-winning side but also established himself as perhaps the most vital cog in a Warriors' front row that is one of the best in the Premiership.
And second row Murphy has also pledged his future to Worcester after signing a new two-year deal following a strong season that has seen him overtake Tim Collier as first-choice lock.
John Brain, Worcester's director of rugby said: "Tony Windo may be one of the oldest players in the Premiership but he has re-established himself as one of the leading props in the league.