Munster v Edinburgh, Thomond Park, Tomorrow 12.45 (Sky Sports 2)
Ireland squad member Stephen Archer is the only promotion in personnel from the starting fifteen which choked up Gloucester last week.
Coach Rob Penney knows this is an entirely different type of challenge, but, at the same time, one which he and his players are familiar with from the PRO12 League.
Whatever chance Archer (right) holds of making the Six Nations squad, he will have to put his best foot forward in front of a second row that includes Paul O'Connell and Dave Foley, who was very impressive on his full debut at Kingsholm.
Munster are right there to take advantage of any slip-up by Toulouse, Toulon or Clermont Auvergne for a home quarter-final.
They will have the edge of knowing most of what they will have to do at lunchtime tomorrow, although Racing Metro will have a strong set out against Clermont Auvergne later in the afternoon.
Edinburgh bring an open attitude to the game and this could lead to a high-scoring shootout given how Munster will be hunting points, or is that tries, too.
Munster: F Jones; K Earls, C Laulala, J Downey, J Murphy; I Keatley, C Murray; D Kilcoyne, D Varley, S Archer, D Foley, P O'Connell, P O'Mahony (capt), T O'Donnell, J Coughlan.
Edinburgh: J Cuthbert; D Fife, N De Luca, B Atiga, T Brown; G Tonks; G Laidlaw (capt); A Dickinson, R Ford, WP Nel, G Gilchrist, I Van der Westhuizen, C Du Preez, R Grant, D Denton.
ULSTER HOPING TO TAME TIGERS
Leicester Tigers v Ulster, Welford Road, Today 6.0 (Sky Sports 2)
This has to be the most mouth-watering of all the final round matches, the winner taking almost all.
Ulster and Leicester know that a win for either not only guarantees the Pool outright, but the likelihood of a home quarter-final.
There is little or no finesse about how the Tigers play. They come straight, hard and often, putting a heavy emphasis on the collision area.
Besides openside Julian Salvi, half-backs Ben Youngs and Toby Flood and full-back Matthew Tait, there are few men of creativity. They like to pose direct questions that demand immediate answers.
Ulster showed against Saracens in last year's quarter-final that they are not immune from freezing on the big day. It has been their downfall. You only have to look at the 2012 Heineken Cup final.
Mark Anscombe's charges have the mettle up front, especially from Rory Best, John Afoa, Johann Muller, Chris Henry and Nick Williams, to trigger a slick backline.
Leicester: M Tait; N Morris, M Smith, A Allen, V Goneva; T Flood (capt), B Youngs; M Ayerza, T Youngs, D Cole, E Slater, G Kitchener, J Gibson, J Salvi, J Crane.
Ulster: J Payne; A Trimble, D Cave, L Marshall, C Gilroy; P Jackson, R Pienaar; C Black, R Best, J Afoa, J Muller (capt), D Tuohy, R Wilson, C Henry, N Williams.
OLD BOYS CAN LIFT WESTERNERS
Saracens v Connacht, Allianz Stadium, Today 1.35 (Sky Sports 2)
Coach Pat Lam has restored his captain Craig Clarke and most-capped player Michael Swift to the engine room as Connacht set about deconstructing Saracens.
Gavin Duffy returns to full-back for Daragh Leader and Dan Parks to controller-in-chief at fly-half for Jack Carty as Lam opts for experience over the raw materials of youth.
"This is a huge game for Connacht Rugby, we all know that. Win and we qualify for a quarter-final in Europe," said Lam.
"Big games require your big players to step up and lead the way, so it's great to be able to call on four of our most experienced players Gavin, Dan, Swifty and Craig this week."
The fact that Sarries coach Mark McCall has decided to go with Charlie Hodgson ahead of Owen Farrell at ten indicates their willingness to spread their game.
Lam was spot on when he said: "If we play as individuals, it will be a long day at the office tomorrow. It's all about our team effort."
And even then ...
Saracens: A Goode; C Ashton, D Taylor, B Barritt, D Strettle; C Hodgson, R Wigglesworth; Mako Vunipola, S Brits, M Stevens, S Borthwick (capt), G Kruis, B Vunipola, K Brown, E Joubert.
Connacht: G Duffy; F Carr, R Henshaw, E Griffin, M Healy; D Parks, K Marmion; B Wilkinson, S Henry, N White, M Swift, C Clarke (capt), A Browne, J Heenan, J Muldoon.