On Rugby: The weekends of truth. More than at any stage over the last eight seasons, it seems to have been thus for pretty much every round of a tortuous Heineken European Cup odyssey for the Irish provinces. Once again, they face the point of no return. Win or bust yet again. Defeat, and they're out.

The prospect of no Irish side making the last eight and thus no European Cup rugby after Sunday week, January 22nd, is too grim to contemplate. Sure, as Wales showed last year, this doesn't necessarily debar a country from scaling dizzying heights in the Six Nations, but the lack of correlation between what Welsh sides achieve in Europe and the performances of their Test team has always been something of a riddle.

Somehow, there seems to be a far more emotional connection between the Irish provinces and the European Cup, and with that Ireland's rejuvenation since 2000.

To miss out entirely would be psychologically devastating, as against the feelgood factor among players and supporters alike were one or more province to keep the flag flying, and not for the first time, potentially prevent an Anglo-French carve-up in the last eight.

For the Munster supporters who justifiably claim "ownership" of their team, this is especially so, and the connection among Leinster and Ulster fans and their teams is every bit as vibrant, if the numbers are less, as with Team Ireland.

As Wasps and Llanelli have demonstrated, no one has a divine right to a place in the last eight, not even Munster, but never in the last eight years has Irish involvement in the knock-out stages looked so imperilled with two rounds of pool fixtures to go.

Even if Munster beat Castres away on Friday, were they to do so without a bonus point and Sale were to maintain their impressive tempo by procuring one in beating the Dragons at home on Sunday, then Sale would be assured of topping the pool. Munster's only route to the last eight then would be as one of the two best runners-up.

Leinster, even with a defeat more and a point less than Munster, look to have a more negotiable run-in, even if the odds are against them too. Were Bath to lose in Bourgoin on Friday, that could even open the door for Leinster to win Pool Five by beating Glasgow and Bath. That could benefit Munster too, but were Bath to beat Bourgoin, Leinster and Munster could both be competing for one of the best runners-up slots. Leinster have a significantly better try tally, but the permutations are endless, with another runner-up liable to progress from the Cardiff-Perpignan pool.

However, that mightn't be the worst-case scenario for Munster. For starters, it could take the edge off Sale's competitiveness when they go to Limerick on Saturday week in the pool finale, although they could thus conceivably run the risk of missing out on a home quarter-final.

Nevertheless, the odds against Munster winning the pool are considerable. Even if they were to remain within five points of Sale, they would thus have to beat Sale, obtain a bonus point and deny the Premiership leaders one as well to overtake them - we're into Miracle Match territory here.

Three seasons ago, a defeat in their penultimate match away to Perpignan generated an even greater sense of foreboding around Thomond Park in the build-up to that unforgettable climax against Gloucester. It's hard to credit it now, but deep down plenty feared for the Thomond Park record when the Cherry & Whites came calling. Indeed, most hadn't figured out the minimum requirement of victory by four tries and 27 points.

Of course, the memories of such days give Munster an inner belief they can somehow pull through again, no less than the timely fillip of Saturday's gritty win away to Edinburgh, and reportedly there was a sense of quiet satisfaction in the visitors' dressingroom at Murrayfield.

Leinster's off-key effort away to Llanelli was the more disappointing, but Munster's need was the greater. Although Munster lead the head-to-heads 6-3, they've lost on three of their four visits to Castres, who (much like Biarritz beating Toulon 57-12 to move to the top of the French Championship) warmed up with a seven-try, 52-28 win over Montpellier on Saturday. That may be no bad thing, and although Yann Delaigue again made them tick, he is now doubtful while Kees Meeuws is sidelined. As influential, though, is Alexandre Albouy, who dictated their higher tempo home game against Montpellier with rapid-fire tap and goes off virtually every penalty.

For whatever reasons, the Brains Trust probably got it right in granting Anthony Horgan, Marcus Horan, Denis Leamy and Anthony Foley a weekend off to recharge their over-worked batteries. It was also deeply encouraging that Paul O'Connell's graph rose another notch, with inspirational tackles on opposing backs on the touchline deep into injury-time and such like, and that Ronan O'Gara patently took criticism of his game to heart.

True, he saw his pass being intercepted by Marcus di Rollo for the try that kept the Scots in the game, but helped by deftly putting Trevor Halstead through the Edinburgh defence early on, the body language, no less than the distribution and kicking, was more like the O'Gara we've come to know.

As much an any Munster player, the durability and reliability of the competition's all-time leading points scorer in 51 of their last 53 Cup ties over the last seven seasons have been a barometer of Munster's well-being. They're in a tight squeeze. One of their tightest ever. But with O'Gara at his best, if anyone can, Munster can.