Anthony Gerrard, the Cardiff City defender, said family loyalties will be placed firmly to one side as he targets "taking down" Steven Gerard, his cousin and the Liverpool captain, in today's Carling Cup final.
The showpiece sees the relatives meet for the first time in professional football.
Cardiff's Gerrard told BBC Sport: "You do anything to win. Steven has an abundance of medals and he's played in these occasions so many times.
"If push comes to shove, one-on-one, with us winning 1-0, then I think he knows he's getting taken down.
"I think that will be vice versa. You do what's best for your team."
Cardiff's Gerrard, who began his career at Everton, recalled his days growing up in Merseyside alongside his more illustrious relative, five years his senior.
"One of my earliest memories is playing footie with him," said Anthony. "Steven and his friends made a goal out of scaffolding and had tarpaulin wrapped around it. It was fantastic. I remember staying off school, getting a kit and putting it on and then playing with him and his mates."
He said he has been in touch with the Liverpool midfielder. "I spoke to Steven and sent him a little joke via text message: 'What are you doing on Sunday?'"
Liverpool's last appearance at Wembley Stadium was in 1996, when they wore cream-coloured suits before losing 1-0 to Manchester United in the FA Cup final.
Anthony added: "I might send him a picture message about the white suits: 'Hope you're wearing them again.'"
Given the family interest, the Gerrards are set to be well represented in London.
"There'll be a large section of the family there," Anthony said. "I got asked for about 80 tickets altogether."