Ireland captain Johnny Sexton believes Andy and Owen Farrell each possess an admirable ability to set aside their close father-son relationship when it comes to a high-stakes rugby match.
The Farrells will be in opposite camps on Sunday when Ireland travel to Twickenham for a titanic Guinness Six Nations clash with England.
Ireland head coach Andy Farrell will hope to see his team clinch the Triple Crown in London to remain on course for a Grand Slam, while England skipper Owen Farrell is bidding to help keep alive his side's title challenge.
Fly-half Sexton has previously seen the pair working together on tour with the British and Irish Lions and fully anticipates a business-like approach from both.
"On Lions tours when they've been together as father and son, you'd never have guessed it," said Sexton.
"They're very close but when they're in a professional environment on the same team it's just like a player with any coach.
"I admired that about them and it's the same when they're opposing. They're very professional and it's just like playing against any other team really."
Coach Farrell has previously faced Saracens fly-half Farrell as part of Ireland's management team but this weekend will be doing so for the first time since replacing Joe Schmidt in the main role.
The younger Farrell will once again play at inside-centre for his country and will be joined in the midfield by the returning Manu Tuilagi, one of four personnel changes made by Eddie Jones.
Asked if 44-year-old Farrell had been able to outline any flaws in his son's game, Sexton replied: "He doesn't have too many weaknesses really.
"If he was c**p that could be a different story and he could be telling us all his weaknesses.
"But he's a world-class player, so it's more his strengths that we've looked at.
"We've all played against him numerous times and we know the type of player he is and how good he is, so we're just preparing for his strengths really."
Ireland, who began the tournament with successive Dublin wins over Scotland and Wales, initially opted for an unchanged starting XV, before their plans were altered by the birth of Iain Henderson's son.
The absence of Ulster lock Henderson paves the way for Devin Toner to come into the second row and make his first start since his shock omission from Schmidt's World Cup squad.
Sexton is delighted to have his experienced Leinster team-mate Toner back in the team to win a 70th international cap, while scrum coach John Fogarty said the squad had sufficient time to prepare for the enforced alteration.
"It's brilliant for him, he's bounced back really well. Obviously everyone has setbacks through their career and he had a big one at a bad time for him but he has bounced back well," said Sexton.
"You saw by the reception that he got against Scotland – I've never heard a crowd cheer so loud for a line-out win.
"We were giving him a bit of stick about it but it just shows what everyone thinks of him. All the lads are delighted for him."
Fogarty said: "Faz (Andy Farrell) was speaking with Iain during the week to see how it would all turn out.
"They spoke a bit last night and this morning and it became clear this morning. We had planned during the week, in the eventuality that it would happen, that Dev is there.
"It's a big ask if he (Henderson) was to come straight in, he missed two sessions, so that bit of cohesion when he's an important person in our line-out and in our team.
"We're delighted for him, a little baby boy."
