Win or bust for Red Army as place in the quarter-finals beckons
By lunchtime tomorrow, Munster will have a fair idea of what they need to book a place back in Thomond Park for the quarter-final. To make sure that they are in the last eight, they simply must win.
They rarely lose at Thomond Park in Europe and Castres are not good travellers, so the conventional wisdom suggests that they'll get the job done.
How comfortable they are remains to be seen.
Normally, getting Castres at home at this stage of the competition is a guaranteed five-pointer, but the French side have a prize to play for here and have named a strong team for their final fixture.
They will be heartened by Leicester's decision to field a close-to-first-choice side for their meeting with Racing 92 at Welford Road. If Castres can pick up four points, deny Munster a losing bonus and Racing lose then they will top Pool 4.
So, this is no foregone conclusion.
The weather will play a major part. The forecast of relentless rain will mean both sides tightening up and with their sizeable tight five, Castres will hope that a less expansive game will play into their hands.
Third in the Top 14, they are a solid side. Their team-sheet doesn't contain the big names that some of their rivals' contain, but there are good players throughout.
"They have big forwards, a very good kicking game, a left-footed fly-half,|" Johann van Graan said this week.
"They don't have a long kicking game, they put you under pressure with a good chase, a very good maul, you need to stop their maul.
"Defensively you just had to look at the Leicester game, they had a very good game; you just need to look at the way they defended, that's a top-quality side that we are playing against."
Munster must adjust their mindset after taking on Racing in perfect conditions in Paris last weekend.
After the shoot-out comes the dogfight and the presence of Peter O'Mahony is a boon to the home side. Although not at his best last weekend, the captain sets the tone for these big days at Thomond Park.
Invariably these fixtures are won up front and Munster have proven their abilities in this regard. Their scrum is strong, their lineout functions well and their back-row is dangerous at the breakdown and dynamic around the pitch.
Conor Murray will take plenty of responsibility on his own shoulders and the conditions could lead to plenty of box-kicks for a hungry back-three to chase.
Munster will hope to exploit any Castres errors to build a lead and put the contest beyond the reach of their visitors.
Discipline will be a real focus after the penalty count again topped 10 last weekend, but if they keep the referee onside then the last eight beckons.
MUNSTER - S Zebo; A Conway, C Farrell, R Scannell, K Earls; I Keatley, C Murray; D Kilcoyne, R Marshall, S Archer; J Kleyn, B Holland; P O'Mahony (capt), C Cloete, CJ Stander. Reps: N Scannell, J Cronin, J Ryan, D O'Shea, J O'Donoghue, D Williams, JJ Hanrahan, A Wootton.
CASTRES - G Palis; K Jaminet, T Combezou, R Ebersohn (capt), D Smith; J Dumora, R Kockott; A Tichit, J Jenneker, D Tussac, A Bias, T Lassalle; Y Caballero, S Mafi, A Tulou. Reps: K Firmin,T Stroe, D Kotze, V Moreaux, B Delaporte, Y Domenech, Y Le Bourhis, A Taumoepeau.
Ref - B Whitehouse (Wales)
Munster v Castres, live, Sky Sports Action, 1.0 tomorrow