In the immediate aftermath of last week's often mystifying encounter at Thomond Park, it seemed impossible to read the runes ahead of this Pool 1 rematch.
Back-to-back matches can be difficult enough to analyse at the best of times, and the latter half of this decisive double date is surrounded by all manner of prognostications.
How well did both sides play last weekend? How much room for improvement can emerge from the combatants tomorrow? Does resistance to change demonstrate strength? Or does a wholesale alteration in personnel admit weakness?
The answers to these questions will point one in the direction of the ultimate victors, and certain assumptions can be made before the much anticipated kick-off.
Keith Earls was arguably one of the best-performing trio last weekend – alongside his captain, Doug Howlett and Man of the Match James Coughlan – and his absence with groin trouble will be a significant loss within the tight confines of Vicarage Road's soccer stadium.
Casey Laulala, Munster's purportedly noteworthy summer signing, has obviously not fulfilled his pre-season potential, despite flashes of his innate ball-playing class, so today wouldn't be a bad place to start producing the goods.
The presence of Ennis man Luke O'Dea in Watford indicates a residual fear Felix Jones and Simon Zebo are also imperilled by injury, and with BJ Botha also struggling up front and the back- row cover weakened by injury, too many doubts attach themselves to this line-up.
Saracens, after a passive display last weekend, were disgusted with their inability to pose any questions of their opponents, but also pleasantly surprised to escape with a bonus point.
Munster supporters travelling today will surely appreciate that Thomond did not necessarily echo the glory days of yore. Indeed, were it not for unforgivable lapses from the tee from the subdued visitors, the result would have been reversed.
"It's not often in sport that you get a chance to rectify things that may have gone wrong the week before," says Saracens head coach Mark McCall.
"But that's the beauty of these rounds three and four matches against the same opposition, and it represents a great opportunity for the squad to put in the kind of performance we know we can deliver.
"We are level on match points and both teams have the chance to take control of the group going into the final two rounds.
"But we have to make sure that our fundamentals and foundations are excellent across the pitch if we are to get the result that we want."
The changes he has made seem primed for that particular purpose, and he has leaned heavily towards instituting the fast-finishing structure that completed last week's 15-9 defeat.
To that end, Owen Farrell starts the game at out-half, with Joel Tomkins, David Strettle, Richard Wigglesworth and George Kruis all coming into the starting line-up from the side that faced Munster in Limerick last weekend.
The newly constituted side, once it demonstrates a little less of the complacent passivity that accompanied last week's effort – several of their number betrayed a sense of post- All Blacks smugness – seem better-equipped to deliver.
Munster will need to absorb the loss of Earls, particularly as their running game still seems to be a stuttering work in progress. It seemed that the figure charged with implementing the back-line cohesion, Simon Mannix, was almost anticipating the Moyross man's loss earlier this week.
"The midfield is all about balance, and each player brings different skills," he says. " James Downey is a very confrontational player, a big physical man who carries the ball and defends well.
"Casey Laulala is very exciting on his feet, great hands, while Earls brings incredible speed and power. They all have different attributes and we can mix and marry it around and get a balance that we feel has the power game with the finesse alongside it.
"Having three players competing for two spots is going to draw the best out of each of them, although it will be frustrating for the one who misses out – but such is life."
Munster will also hope to attack the home line-out with as much effectiveness as they did last weekend, but the main onus will be on controlling their own elements, particularly the indiscipline issue that continues to dog them, and the hitherto less than reliable delivery of their own set-piece ball.
"Every week we are making a bit of progress, tangible progress," confirms head coach Penney. "The belief thing comes with a bit of success, having the results go your way, and that's all adding to the well. We are not out of the pit, but we are on the upwards curve."
That McCall feels his own side may be beginning to scale a similar gradient compounds the sense of intrigue. None of the English sides impressed last weekend, understandably after a solid month of international competition, and the extra week's preparation will have benefited them considerably.
This one could be a similar arm- wrestle to last weekend. Saracens were probably expecting a more expansive Munster on their home turf and, having conceded considerably at the breakdown, they will this week attempt to impose their own strictures upon the game.
For all the doubts surrounding Munster, they did still win last weekend and, as they collectively acknowledge, they remain masters of their own destiny.
"It was very heartening," says Penney in anticipation of tomorrow's tussle. And I think they'll be very tough at home this week for those reasons. They've a lot of pride and they'll be determined not to let something like that happen to them again. But we're improving and building confidence. There'll be fireworks."
As to whether Munster have enough firepower is a different question. The evidence indicates that they have less room for improvement than their hosts.
The greatest tribute to Munster's renowned resourcefulness would be a thorough rebuttal of that argument.
Saracens – A Goode; C Ashton, J Tomkins, B Barritt, D Strettle; O Farrell, R Wigglesworth; R Gill, S Brits, M Stevens; S Borthwick (c), M Botha; G Kruis, W Fraser, K Brown. Reps: J Smit, M Vunipola, P Du Plessis, E Sheriff, E Joubert, N de Kock, C Hodgson, C Wyles.
Munster – F Jones; D Howlett (c), C Laulala, J Downey, S Zebo; R O'Gara, C Murray; D Kilcoyne, M Sherry, BJ Botha; D O'Callaghan, D Ryan; D O'Callaghan, P O'Mahony, J Coughlan. Reps: D Varley, W Du Preez, S Archer, B Holland, P Butler, D Williams, I Keatley, L O'Dea.
Ref – J Garces (Fra).
Saracens v Munster, Live, Tomorrow, Sky Sports 2, 3.0
Three things Munster must do
1 Centre of attention
Casey Laulala to deliver a big performance – he was bought to provide Heineken Cup class and he hasn't done so.
2 Aerial wars
Munster destroyed one of the best line-out operations in the business last weekend; were they to be so bold as to attack away from home with equal fervour, this could utterly undermine the Saracens challenge.
3 Dominate breakdown
Munster were also superior in ruck and maul situations last week, and were they to wrest as many turnovers once more, they would be one step closer to a win.