Rio Ferdinand has vowed their will be no brotherly love on show once the first whistle blows at Upton Park on Sunday.
For the first time in their professional careers the Ferdinand brothers Rio and Anton will go head to head this weekend as Manchester United look to keep their slim Premiership title hopes alive with a victory at West Ham.
Up to 35 members of the Ferdinand clan will be at the game, with loyalties in the family camp so divided, some will be wearing half and half West Ham and Manchester United shirts.
And while Rio admits he is delighted at Anton's progression through the Hammers' academy ranks, just for once, he hopes his little brother has a stinker.
'I used to coach him as a kid on the grass on our estate,' Rio told the Manchester Evening News.
'I just hope I didn't do the job too well.
'He is my brother and I want him to play well but I want to win, so I hope he cannot keep Wayne Rooney and Ruud van Nistelrooy quiet.'
Amid the elder Ferdinand's trials and tribulations with the Red Devils this term, there have been some unkind suggestions Rio is no longer the best defender in his family.
Twenty-year-old Anton still may have some way to go to fulfil that bold statement as his hesitant performance against Tottenham last week proved.
But, their weekend rivalry aside, no-one could be more delighted than Rio at the progress his brother has made.
'It was always my wish to see my brother make it as a professional after I had gone into the game but you never believe 100% that it can happen,' said Ferdinand.
'But I knew he had the talent and he has proved good enough to do it at the top level consistently.'
Addding fourther spice to the brothers' encounter, West Ham boss Alan Pardew has asked Anton Ferdinand to mark his sibling whenever Manchester United have a set-piece in a dangerous position in the Upton Park clash.
'He is our dominant header, which he proved last Sunday with a great goal,' said Hammers manager Alan Pardew.
'I keep saying to him he has to be that dominant figure. He has to pick up the biggest player, which at United will probably be his brother, so he has a huge responsibility for us.
'As well as natural defending he has to be our big, assertive player at set-plays and that's an important role.
'His brother is that little bit older and he might be over-awed by it. I don't know their relationship that well although I know they are really close and speak regularly.'
Rio, 25, began his career at West Ham before Leeds lured him north five years ago in an £18million move and he soon became a mainstay in the national squad, moving on to Old Trafford.
Anton is already following in his footsteps on both levels, having established himself as part of the England Under-21 set-up.
Goalkeeper Roy Carroll, who left United in the summer, is expected to return at the expense of Shaka Hislop, who has played the last five matches.
Manchester United striker Louis Saha is determined to make up for lost time after making his first senior appearance of the season against Villarreal this week.
Saha knows he has something to prove after a nightmare couple of years since his £12.8million arrival from Fulham.
The 27-year-old scored six goals in his first eight games for the Red Devils but has since been blighted by a succession of fitness problems, including lengthy absences due to hamstring and Achilles complaints.
'I have been waiting a long time to get back on the pitch again and I just want to be involved in every game,' said Saha.
'It was great to get back on the pitch but it almost felt strange because I have been out for so long.
'I need my fitness back and I will only get that by playing competitive football. But even if I am struggling on the pitch, it is better than struggling off it.'
With Gary Neville accompanying Saha on the comeback trail and Roy Keane's contribution to the Red Devils' cause now consigned to the history books, Ferguson should have only three senior men missing - Gabriel Heinze, Ryan Giggs and Quinton Fortune - for the trip to east London.