If incoming Crusaders coach Rob Penney didn't have a hard enough task in replacing Scott Robertson at the helm of the Super Rugby champions, he'll have to do so without the services of Richie Mo'unga in the No.10 jersey.
Since 2017, Mo'unga has been at the centre of the Crusaders' Super Rugby dynasty under Robertson, winning seven titles across three separate competition formats.
But the end of this year's Rugby World Cup signalled the end of Mo'unga's time in New Zealand for the forseeable future, with a three-year deal in Japan to come into effect from 2024 and beyond.
While there could be potential for Mo'unga to continue as an All Black - should New Zealand Rugby move away from its locals only selection policy - his time with the Crusaders is all but done.
And, as Robertson moves on to coach the All Blacks, the likes of Mo'unga and Sam Whitelock leave huge holes in the Crusaders' ranks.
Whitelock, bound for French club Pau, leaves with the likes of Quentin Strange and Zach Gallager bidding to replace him alongside Scott Barrett as a second row starter, but Mo'unga's absence will be harder to plug.
As the Crusaders named their playing roster for 2024, the trio of Fergus Burke, Taha Kemara and Rivez Reihana loom as the only specialist first-fives currently on the club's books.
Burke, 24, looms as the most senior option available but will miss most of 2024 after suffering an Achilles injury to end this year's NPC campaign with Canterbury.
That leaves 23-year-old Reihana and 20-year-old Kemara as the immediate options to replace Mo'unga when the 2024 season begins early next year.
For coach Penney, though, there is complete confidence in whoever is picked to do the job.
"You can look at, I guess, the last 15 or so years, there's a 'before Richie', there's now going to be an 'after Richie,'" said Penney. "We hope the 'after Richie' is consistent with the 'during Richie.'
"Our job is to try to mitigate the loss, promote the next wave and make sure the environment is such that people feel as though they're not burdened with the role they're provided with, and that people around them understand their role in supporting the pivotal position that it is.
"If we can do those things, the team will be successful on the back of it. The way the Crusaders operate historically, and I don't see that changing, it's a heavily player-led environment.
"Those mature players that have been around and had success, they'll continue to lead and provide support for whoever's wearing the 10 jersey."
One player who won't be considered to fill Mo'unga's shoes, though, is Wales great Leigh Halfpenney.
The 34-year-old has signed a one-year deal with the Crusaders and himself admits he'll cover No.10 if needed.
But as far as Penney's concerned, Halfpenney is first and foremost a fullback.
"I've never seen him do that, that's not why we've picked him," Penney explained. "We've got really capable inside back cover.
"We wouldn't envisage him having to play there. He's come here with a specific job in mind around a bit of extra maturity and cover in the backfield, and supporting the growth and development of some of those younger players.
"He can play more than one position but we're really looking at him as a 15.
"I'm very excited about the growth of Taha and Rivez and then Ferg [Fergus Burke] is coming on the scene a bit later on.
