Leo Cullen remains consumed by the challenge of leading Leinster’s pursuit of a fifth Champions Cup star despite another painful defeat in a final.Speaking ahead of Saturday’s URC quarter-final against the Lions at the Aviva Stadium, the province’s head coach stated his belief that Leinster would not improve if he walked away after 11 years at the helm.However, the 48-year-old admitted all aspects of the province’s set-up will come under review at the end of the season following last weekend’s 41-19 defeat by Bordeaux Bègles. That assessment will encompass training methods, match preparation and tactics, including the blitz defence introduced by Jacques Nienaber.Leinster’s latest setback extended their wait for Champions Cup title glory to eight years. It was their fifth defeat in a final since their last success in 2018. Cullen described the days that followed as a “grieving process” for his squad, a mood reflected in his demeanour during a media briefing on Thursday.Yet when asked whether he still had the appetite to lead Leinster into another campaign, Cullen provided an energised response. “Yes, absolutely. I 100 per cent believe that,” he said.“It’s difficult to deal with some of these days because there’s the weight of expectation.“In many ways, it’s a win-or-bust mentality. We do everything we can to win the Champions Cup, so when we don’t, there is a bust mentality attached to it, even though we keep getting there year after year.”Leo Cullen and Jacques Nienaber have much to reflect on. Photograph: Nick Elliott/©INPHO Cullen pointed to French dominance in the competition, with clubs from the Top 14 having won each of the last six tournaments.“There’s lots of things that we will do a real deep dive on,” he said. “The teams that we’re playing against are different. There have been six French winners in the last six seasons.“When was the last time a team from our competition [URC] was in a final, other than ourselves? It’s a long way away.“We’re desperate to be the top team in club rugby. That’s exactly what we want, but it does feel like boom or bust at times.”The review, Cullen suggested, may extend to questions around mentality and approach, although he defended the decision for the team to undergo a defensive evolution under Nienaber, a two-time World Cup-winning coach with South Africa.“I wanted to bring a defensive system here that sees us attacking the opposition when they have the ball,” Cullen explained. “I wouldn’t see it as a defensive team; I see it as a very aggressive attacking team on both sides of the ball. “That’s an important mindset shift because we’ve lost finals in different ways over the years. We wanted to change the way we think about that side of the game.”[ Matt Williams: Leo Cullen helps make Leinster amazing, but big changes are needed under himOpens in new window ]Cullen also referenced the structural constraints within which Leinster operate, particularly compared with some of their French rivals.“We know we have different rules. We can’t go out and sign a ton of non-Irish-qualified players,” he said, although he later confided that there were “conversations” ongoing about possible signings.“If we do bring players in, that has to be in connection with the IRFU. There are lots of different factors at play.“There’s already so much planning going into next season. For me to walk away from this, that’s not going to make it better.“I’ll be fully committed as we finish this season and move into next season. We’ll go steaming into it again, like we try to every single year.”Leinster must attempt to turn the page quickly with the URC playoffs under way this week. Retaining the title would salvage something positive from an inconsistent season for Cullen and his players.James Lowe will make his 100th appearance for Leinster on Saturday. Photograph: Grace Halton/©INPHO He has made eight changes to the side that started the final in Bilbao. Garry Ringrose, Tommy O’Brien and Jack Conan are unavailable through injury, while Rónan Kelleher misses out with a neck problem.Sam Prendergast returns at outhalf, despite missing out altogether in Bilbao. Harry Byrne is included among the replacements, while Connacht-bound Ciarán Frawley, who impressed off the bench for Byrne last week, is omitted from the matchday squad.“There’s so much potential in the province,” Cullen said. “We just need to keep going after that all the time.“I’m as consumed by it as I ever have been. It is consuming, but I love doing it. When you have days like you had at the weekend, it’s brutal. But that’s when you show what you’re made of.“Leaders need to get back out there and lead the group. There’s no benefit in hiding away from any of this.“We need to get out and confront it and go again. That’s what we can control at this moment in time.”James Lowe, who was among the non-playing cohort in Bilbao, will make his 100th appearance for Leinster on Saturday. The 33-year-old is level with Shane Horgan on 69 tries for the province but, if the home side lose on Saturday, it could be Lowe’s last game in blue as negotiations continue over a new contract.“Together as a team, we need to do better, but someone like James brings proper genuine power, change-up and his ability to finish when you get close to the tryline,” said Cullen.“He’s been brilliant for the group. I’ve loved working with James. Listen, he’s a great character. Hopefully he kicks on. Bar Shane Horgan, everyone will be delighted if he does score a try this weekend.“We need to be able to dust ourselves off and go at it again and do whatever we can to get through this week. Hopefully there’ll be another week because if we don’t get it right, there is no other week.“It’s hard to even contemplate what that would feel like.” LEINSTER (v Lions): Hugo Keenan; Jimmy O’Brien, Rieko Ioane, Jamie Osborne, James Lowe; Sam Prendergast, Luke McGrath; Andrew Porter, Dan Sheehan, Tadhg Furlong; Joe McCarthy, James Ryan; Max Deegan, Scott Penny, Caelan Doris (capt).Replacements: Gus McCarthy, Alex Usanov, Thomas Clarkson, Diarmuid Mangan, Josh van der Flier, Jamison Gibson-Park, Harry Byrne, Robbie Henshaw.