Brotherly bragging rights will go on the line when the British & Irish Lions kick off their Australian tour against the Western Force at Optus Stadium.
The Lions arrived in Australia licking their wounds after suffering a shock 28-24 loss to Argentina in Dublin last weekend.
Irish scrumhalf Jamison Gibson-Park (glute) and winger Hugo Keenan (calf) joined the Lions camp under injury clouds and are in doubt to take on the Force.
The on-field rivalry is set to be fierce on Saturday as the Force, powered by Wallabies such as Nic White, Dylan Pietsch, Tom Robertson and Darcy Swain attempt to inflict an early psychological blow on the Lions.
There will also be rivalry off the field, with Lions assistant coach Andrew Goodman keen to get one over his brother Chris, who works at the Force as their general manager of rugby.
"Yeah, a bit of added spice there," Andrew said after Lions training on Wednesday.
"It's been great to catch up with him and his family, and I've got my older brother over as well, so a bit of a family occasion for us.
"My nephews were asking who they reckon grandma is going to be supporting, so I'd say she'd have both (colours) on."
Andrew revealed it's not the first time the brothers have gone head to head, with the Force taking on an Emerging Ireland side late last year.
"I was helping out with Emerging Ireland, so we had a little battle there," he said.
"We got up in that one, so it's 1-0 at the moment.
"This will be the second one in a number of months, so there's always some good banter that goes on.
"I obviously keep a good eye on the Force, because I'm wanting them to do well during the Super Rugby season."
Lions head coach Andy Farrell has forecast making widespread changes for the game as he looks to find the right combinations among his 38-man squad.
Goodman said it was easy to identify the areas his team struggled with against Argentina.
"Turnovers. There were a lot of turnovers, a lot of forced offloads," Goodman said.
"We threw five intercept passes, just from not sighting a target.
"If we can get more cohesion with our attack in terms of finishing our last pass, we will see an improved effort.
"When there's four countries coming together, there are going to be little combinations that you need to build, and it can take time.
"But it's not an excuse, just a reality, and something we're looking to get better and better with every time we go on the training track."
The Lions beat the Force 69-17 when they last toured Australia in 2013.
