It was all going a bit too well for Leinster over the past fortnight. Something had to give.
They had laid waste to the theory that their squad was undergoing a crisis of confidence under new coach Joe Schmidt, thanks to a second-half stormer against Munster, and were en route to hammering Racing Metro when Brian O'Driscoll's hamstring went.
The initial news is that the muscle injury is not as bad as first feared, raising hopes that the Ireland captain could even make a shock return within seven days of hobbling off -- on the hallowed turf of Wembley Stadium.
But instead of basking in the glory of a five-try demolition of a big-spending French side packed with even bigger names, Leinster have been fretting over the fitness of a man who may not be captain, but is one of the province's key leaders.
With the actual captain Leo Cullen also battling to be fit for Saturday, it is hardly an ideal scenario for Schmidt and his right-hand man Jono Gibbes, who confirmed that the IRFU will be "in the picture" when a decision is made on whether to start O'Driscoll.
"I'd say Brian, Joe and the medical team will sort of collaborate," the forwards coach said. "He's a pretty experienced player and has been through these sort of injuries before, so he can give good insight.
"But it will be a collaboration. I'm sure the Irish medical team will liaise with the Leinster medical team and I think everyone will be in the picture.
"We had a pretty light Monday/Tuesday last week and got most of our work done on Thursday, so for guys like Brian or Leo, those couple of days are light at the start of the week -- he (O'Driscoll) really needs to get through Thursday, it's just kind of worked out like that."
The former All Black certainly sounded more confident when discussing Cullen's return from a shoulder injury, and he believes the skipper would make a huge difference against last year's Premiership finalists.
"Everyone knows Leo's track record and what he offers to the team. It'd be great to have him for what will be a pretty hostile game at Wembley," he said. "Leo's temperament and leadership skills would be great to have.
"Again, we'll make the decision later in the week after we see him get through a bit of work.
"We're testing him and waiting to see how he feels about it. He knows his body better than anyone so ultimately it's his call, we're just facilitating the work that he needs. I think he'll be pretty close this week."
Saracens are lying third in England's premier competition and although they lost in France last weekend, they did so playing well.
Their former Springbok director of rugby Brendan Venter has surrounded himself with plenty of his countrymen at Vicarage Road.
But Gibbes doesn't necessarily believe the presence of 10 South Africans and a Namibian in their squad makes Saracens a different proposition to other English clubs.
"They looked really good against Clermont and were probably unlucky not to get some reward," he said. "I think they are probably going to play at a different pace to what Racing did at the weekend.
"They have just assembled a squad and they are sort of playing the coach's style. He happens to be a South African and there seems to be a couple of South Africans in the team, but I wouldn't read too much into their psyche or mentality.
"Saracens have got a really experienced pack. Deon Carstens, (Steve) Borthwick, the man in the middle (Schalk) Brits is on fire. So I think they can look to disrupt us.
"But I think the positive out of the weekend was that Racing scrum a certain way and we imposed a couple of things upon them and I think that was a pretty positive thing for us."
From a player's perspective it seems like the trip to the 90,000-capacity Wembley is whetting most appetites. For the in-form flanker Sean O'Brien, it represents another chance to stake a claim for a starting spot in the November internationals.
And the Tullow man believes Leinster's big-game experience will help them in one of the biggest stages in world sport.
"None of us have ever played there before and some of us have never even been there before, so it will be something new," O'Brien said. "It'll be something different and everyone's looking forward to getting over there.
"We do have a lot of experience as a side of playing in these big games. There's a good mix out there, with younger lads who have played in games like these last year and the year before. We all know what it's about and there will be no fear going over there.
"It is an incredibly hard group. We've only got one win and there's a long way to go in the pool stages. We have to be on our game every single week -- that's what it will take to get out of this group."