Leinster must try to replicate the success of last season without the services of Joey Carbery but Rob Kearney admits that the switch was for the good of Irish rugby.
The Leinster full-back is the most decorated player on the island: four Champions Cup medals, four Six Nations titles, including two Grand Slams, three Pro League wins and a Challenge Cup.
So he knows, more than most, what it takes to get over the line, and that the absence of the talented 22-year-old Athy man - who moved to Munster in May - makes the job of adding to that illustrious medal haul with his province, the current European and domestic champions, more difficult.
That said, the move has the potential to strengthen Joe Schmidt’s hand come World Cup time next year.
The theory being that, in tandem with Conor Murray, Carbery gets much-needed game time at out-half and should anything happen Johnny Sexton, the replacement has the experience to step up.
It's not that Carbery has been found wanting in any of his 12 Ireland appearances, it’s more that Schmidt didn’t want to be left in the situation he found himself in 2015.
Facing into a World Cup quarter-final against Argentina, the Ireland boss was low on supplies.
Ian Madigan came in for the injured Sexton, while Sean O’Brien and Paul O’Connell were also missing.
The Pumas duly blew Ireland out of the water and for the eighth tournament running there would be no semi-final place.
"From a national perspective, it’s a very good move," Kearney told RTÉ Sport.
"We learned some lessons at the last World Cup with Mads not getting a huge amount of game time.
"You have to look at it from both perspectives.
"There was a move for him to play more at out-half but obviously from a national perspective the more game time you get at 10 the better it will be for the national team.
"It was a tough decision for Joey, we could all sympathise with how difficult a decision it was for him but he needed to do what was best for him.
"What is a big loss for us is obviously a huge gain for Munster."
Another team-mate who knows what Leinster have lost is Sean O’Brien, who is recovering from a shoulder injury having played just six times for the province last season.
Speaking at the launch of Leinster's new innovation partnership with BearingPoint, the back row said: "We’ve lost a very good player.
"Someone who came up through the system and someone who Leinster have invested a lot in.
"But Munster have gained a really good enthusiastic young out-half, who is incredibly talented, works incredibly hard and has a good few strings to his bow.
"He’ll bring that down there and add a lot to their set-up and with the players they have he’ll fit in pretty well.
"He’s going to add value but it’s very hard to say if he’s the key to [success].
"There’s a lot of things in their set-up that I’m sure they are trying to improve...he’ll definitely have them in a better place."
