With Pool Four containing further threats in the shape of resurgent Cardiff Blues and unpredictable French side Bourgoin, any back-to-back European crown for Munster will be achieved the hard way.

“We spent many seasons trying to win the trophy – and we went very close on a number of previous occasions – so it was a tremendous feeling when we were fortunate enough to win it last season,” said Ireland scrum-half Stringer, whose opportunist solo score finished off Biarritz in a thrilling Millennium Stadium final five months ago.

“But we realise it will be an extremely difficult task to retain the trophy, as we get a sense that it is the goal of every team we play against to try to beat the European champions.

“We are fully aware of what is in store for us, and we will have to raise our level again in order to retain the trophy.

“In the last few seasons we haven’t started the group stage that well, and you cannot really afford to lose more than one game. When you look at the groups, there are no easy matches.”

Leicester boss Pat Howard has recalled England wing Tom Varndell following a short loan spell at National League One club Bedford and his recovery from a minor knee injury, while former Munster fly-half Paul Burke has beaten off Andy Goode’s challenge for the number 10 shirt.

Tigers are unbeaten at home since Heineken Cup opponents Biarritz defeated them in January last year.

Cardiff travel to Bourgoin tomorrow, quietly confident of achieving a first Heineken Cup victory on French soil following 11 failed previous attempts.

Impressive victories over Wasps and Saracens in the EDF Energy Cup this season confirmed an ongoing improvement under head coach David Young, suggesting they could feature prominently in the Pool Four shake-up.

“It is a massive challenge, but it is one we will relish and we will attack it with everything we have got,” said Young.

“No-one gives us a chance of going through – I don’t think anyone is going to put money on us reaching the quarter-finals – so it is up to us to prove them wrong.

“If you look at where we were this time last season, then we are miles in front of that. We have shown with our performances that we are really going out to win games, not just hoping we can win them.

“Someone has to win the group, and I don’t see why it cannot be us.”

French giants Toulouse, the only team to land three Heineken Cup final triumphs, face a tough Pool Five opener against Ulster in Belfast tomorrow.

And their French championship form does not bode well for the Ravenhill encounter, having suffered a 46-9 loss to Clermont Auvergne just a fortnight ago.

“Everyone knows there are certain games you are not expected to win in this tournament, and away to Ulster is definitely one of them,” claimed Toulouse coach Guy Noves, whose starting line-up does not include Wales star Gareth Thomas or goalkicking scrum-half Jean-Baptiste Elissalde.

“To be honest, I would be feeling under more pressure if we were playing against the likes of Calvisano away, as that is a tough game we know we cannot afford to lose.

“It is true that we are approaching this game from a difficult position. We have not had an ideal start to the season, and getting a win away to Ulster is a massive task for us.”

Elsewhere tomorrow, runaway French championship leaders Stade Francais visit Calvisano in Pool Three, with Perpignan travelling to Pool One opponents Treviso.

Apart from Leicester’s showdown with Munster, the Heineken Cup schedule on Sunday sees Wasps hosting Castres and Northampton in action against last season’s runners-up Biarritz at Parc des Sports Aguilera.

Saints are not expected to trouble Biarritz, especially with fly-half star Carlos Spencer absent through suspension, but their World Cup-winning hooker Steve Thompson returns after injury less than a week before England head coach Andy Robinson names his autumn Test squad.

“I am really not thinking about England at the moment,” insisted Thompson. “I just want to go down to Biarritz and get a result for Northampton.”