Leinster coach Joe Schmidt is preparing the defending champions for a tough European battle.
The Irish province go in search of an unrivalled hat-trick of back-to-back Heineken Cup titles. However their New Zealand coach says their previous victories mean nothing and they must start afresh when they kick off their campaign against Exeter.
"It's very much a fresh start," said Schmidt on the Rugby Club.
"We decompartmentalise it game by game and do not even have the Pool in mind. For us it is all about Exeter and making sure that we are as ready as we can be because the margins are so fine. If you lose that first game then you are really scratching to stay in."
Pool 5 is one of the toughest groups with many people expecting Leinster and Clermont Auvergne to battle it out for top place - and whoever loses that battle still going through to the knockout stages. Schmidt does not think it will be a two way battle though and says they will face stiff challenges from Exeter and Scarlets.
"The Pool we are in is probably not one that Clermont or ourselves would like to have - neither of us are too happy the way Scarlets are going either," laughed Schmidt. "Or Exeter for that matter - I watched them play Northampton and thought they were very good. Across the board it is a very tough Pool.
"I think Scarlets are a dark horse from our pool - they have played some super rugby in the last few weeks. With the Welsh backline guys like Scott Williams, Jonathan Davies, George North and Rhys Priestland they have got a fantastic mix to attack from the back.
"Harlequins are not really a dark horse but I think they are a horse that you would not mind putting a little bit on because they are in a really good position. I hate to mention Clermont because they are in our Pool - and they are not really a dark horse. Racing Metro, they really put it on against Clermont a couple of weeks ago. They could be a dark horse."
The English and French teams believe the current format favours the Celtic nations as they do not have relegation and promotion and do not have to worry about qualification for Europe. However Schmidt, who coached Clermont Auvergne for three years, believes it is all about getting the balance right.
"I do think there is a luxury in knowing that you are not going to be relegated, we know we have to finish in the top three of the four Irish provinces. You cannot afford to be off the mark too much, but I know the scramble that is the Top 14 too.
"With Clermont we always did finish in the top four so it did not really matter but it would be tough going because the games are pretty combative week to week.
"One thing for Leinster is that we have made a minimum of seven changes per game in the first five games in the Pro 12. That means that we have got a massive lack of continuity - it is way too much. There are advantages to having guys coming in and out but there are real disadvantages as well."
Lions tour calling?
With a British and Irish Lions tour on the horizon many players will be using the Heineken Cup to impress Lions coach Warren Gatland, however Gatland will also be looking for his coaching staff and Schmidt admits he would jump at the chance.
"It is the pinnacle of rugby involvement in this hemisphere. It would be a super chance for whoever does get that opportunity. I know Gats (Warren Gatland) a little bit and I would say he would be able to give me a call without too much trouble, I don't hold out much hope, but whoever does that job will have a fantastic tour and an exciting time for them."