They may have stretched their unbeaten run to 12 games in all competitions with another scratchy success away to Scarlets last weekend, but the next two weekends will define this Ulster team.
"We've known this from a long way back," conceded No 8 Roger Wilson, who returned to his native province this summer after helping Northampton reach the 2010-11 final during four seasons in the English midlands.
Unlike their Irish rivals, however, the Saints do have a tad more wriggle room at their disposal in the back-to-back exchanges, with the likelihood that both of these heavyweights may emerge from this pool.
But Europe is not a place for gambling. Given the fact that this hugely ambitious Ulster outfit aim to at least match their achievements of last season, they know that a brace of wins is more likely to nab them a vital home draw than merely a five-point haul.
"If we want to be perceived as being up there with the best teams in Europe, then these are the types of games that we simply must win," declared Rory Best with unwavering candour.
Ulster have been undoubtedly buoyed by their league form this term, particularly in the manner that they have ridden the loss of some key performers – Stephen Ferris, Johann Muller, Best, Wilson – which has enabled them to develop a range of viable options in most positions.
Last season, their modus operandi was typified in their famous Thomond Park mugging of Munster when they started and finished with the same 15 players; in the short time since, they have developed a greater flexibility.
And they have learned one of the great lessons of leading sides – how to win ugly – something they have done in the last three outings, as everyone within the camp concedes.
But relating Pro12 form to the Heineken Cup arena is like assessing the Christmas festival at Leopardstown on the evidence of point-to-points. The players aren't foolish.
"We know we haven't really been tested this season," affirmed Wilson. "Although there have been a few changes over the last few weeks, we haven't really been performing.
"Now we're coming in to a really testing time of our season and psychologically we need to step it up a level. We can't afford any slip-ups.
"We know the reality is that you can't perform 100pc every week and we know we've ridden our luck a little bit. But this is one of those weeks where we really need to be on top of our performance."
In Europe thus far, they have proceeded with admirable efficiency, even if their bonus point against Castres was achieved a little too breathlessly.
They still have to travel to France, where the Saints have already succumbed – just – but the complicated mathematics can easily be obviated by a pair of wins this week and next.
Easier said than done, of course. Ulster have rarely travelled well; they are at their worst in England, a legacy of a decade's appalling underachievement following their 1999 success.
Northampton have come unstuck against Irish sides more often than any other, however, losing eight of 12 and the last three, in which they've conceded 107 points – encompassing a tonking at home from Munster last season and that incredible second-half submission against Leinster in the 2011 final.
A detailed analysis and a glance at the team line-ups indicate that this one will be all about set-piece and breakdown; hence there should be little surprise in the exclusion from the Ulster line-up of Craig Gilroy. Big men are required for some heavy duty lifting. Northampton have lost a few of theirs, the injured Ben Foden, their former battering ram James Downey and, of course, Wilson.
"Everything they do well comes through their strong set-piece," said Wilson. "I've learned a few things, but there isn't a massive complication in terms of how the Saints play the game – although it's highly effective.
"I'll have a couple of nuggets that might come in handy. It's all very well saying it's a limited game plan, but they do it well and few teams are able to counteract it."
Northampton have conceded more turnovers (38) this season than any other team in the Heineken Cup, while, conversely, Ulster have been kings of winning turnover ball thus far (21 to Northampton's 9).
Northampton, with all hands on deck, including the conquering heroes of Twickenham, who downed the 20-game unbeaten All Blacks, wallow in the efficiency of their scrum and line-out.
So, too, do Ulster, however and, regardless of the scruffy nature of their recent form, their set-pieces have predominantly been reliable.
Both sides have established finishers out wide and, with forecasted conditions benign, the side who edges the primary possession will be confident of profiting from their three-quarters.
It is indicative that the Saints have preferred the enigmatic Ryan Lamb to the prosaic Stephen Myler as their choice of pivot, but then again, Ulster boast the inordinately influential Ruan Pienaar, of whom England assistant coach Andy Farrell opined that he "never gets tired of doing the right thing."
Either way, it will either be unlucky 13 for Ulster or they'll be celebrating Tommy Bowe's 50th Heineken Cup appearance with their 50th competition win.
A knockout blow is unlikely to happen; Ulster just want to ensure they don't get their nose too bloodied and escape with at least a point. But if they are really credible about contending in this competition, a win would seriously underline their credentials.
Northampton Saints – B Foden; K Pisi, G Pisi, D Waldouck, J Elliott; R Lamb, M Roberts; S Tonga'uiha, D Hartley (c), B Mujati; S Manoa, C Lawes; C Clark, T Wood, G-J van Velze. Reps: M Haywood, A Waller, P Doran-Jones, M Sorenson, P Dowson, L Dickson, S Myler, T May.
Ulster – J Payne; T Bowe, D Cave, P Wallace, A Trimble; P Jackson, R Pienaar; T Court, R Best, J Afoa; J Muller (c), D Tuohy; I Henderson, C Henry, R Wilson. Reps: N Brady, C Black, R Lutton, R Diack, N Williams, P Marshall, L Marshall, C Gilroy.
Ref – L J Garces (France).
Northampton v Ulster,
Live, Sky Sports 2, 8.0