Ulster coach Mark Anscombe has admitted that captain Johann Muller is unlikely to be available for the trip to Llanelli where, on Saturday, Scarlets will provide his side's last challenge ahead of the two-week break for international action.
The South African lock bowed out in the opening quarter of Ulster's 39-21 victory over Cardiff Blues at Ravenhill with a calf injury.
And if, as Anscombe suggested, he is unavailable for the weekend's Parc y Scarlets showdown, Ulster will have a problem.
Iain Henderson (toe) is sidelined, too, and with Dan Tuohy – scorer of two of Ulster's five tries against Cardiff – missing on Irish duty, the engine-room has taken a massive hit.
"Johann, at this stage, I'd say is pretty doubtful. He won't be around next weekend," Anscombe said. "And with Dan going, that hurts us a bit
"But Lewis (Stevenson) came on and did a good job and we're fortunate to have someone of his capabilities and experience. Now we've just got to find someone else to lock up with him next week."
Neil McComb looks the best bet, though Robbie Diack has deputised there in times of crisis in the past.
The news on hooker Rory Best – who twisted an ankle – is better, for Ulster's Kiwi coach had good news for his fellow-countryman, Joe Schmidt, ahead of his first game in charge of Ireland, at home to Samoa on Saturday, November 9.
"All going well, he'll be fit and available. It's two weeks away, so fingers crossed. I think everyone's hopeful that he should be alright for that," Anscombe said.
Tuohy's demeanour in the wake of Friday night's demolition of Cardiff really said it all. Right now, Ulster are on song
Six successive victories over Connacht, Treviso, Ospreys, Leicester Tigers, Montpellier and Cardiff find them topping Pool 5 in the Heineken Cup and sitting fourth in the RaboDirect PRO 12 race.
They outscored Friday night's Welsh guests by five tries to two, banking a bonus as a reward for their at times excellent creativity.
Tuohy's brace was augmented by scores from the magnificent Jared Payne, Luke Marshall and Andrew Trimble.
Sitting alongside Anscombe and 20-year-old Stuart Olding – another of Ulster's stand-out players – Tuohy was smiling broadly when he said: "I gave Stu a few tips at the start of the week, because I started my career off at full-back or the wing so I was telling him and Jared how to rotate between the three.
"I just proved today that it's not as hard as it looks; it's pretty easy out there," was his teasing assessment of life out wide in the back line.
Then turning more serious, he said: "No, they were team tries really. It could have been anyone on the end of it."
Having just completed a highly impressive first shift as Ulster's full-back, young Olding expressed his satisfaction with a good night's work.
"I'm very happy with it," he said. "In training I was running a bit at full-back so I had an idea I could be playing there some time soon.
"I'm just delighted to be in the starting 15 and I was happy with how it went.
"Some things were pretty rusty, but it was my first 80 minutes this year and only my third or fourth game this year so plenty to build on."
With Muller (left) exiting in a bruising first quarter, it fell on Tuohy to organise the Ulster line-out.
"We lost a couple of them," the big lock conceded.
"At the start of the season it wasn't functioning to our high standards – we set high standards in every area of the game and that's our fundamentals, scrum and line-out – so it was just pleasing that throughout the game it got better, because it was a little bit scrappy to start with.
"But hopefully when Johann goes off the transition can be seamless."
With Cardiff's line-up including a pair of open-side flankers, Ulster had known what to expect at the breakdown, so although they had little time to prepare they were not found wanting when it came to imposing themselves there.
"Yeah, they picked two sevens, so we knew that was an area they were going to target," Tuohy said.
"We didn't really get a chance to do that much work on it because of the six-day turn-around and back-to-back Heineken Cup games so it was just something (where) we had to rely on our knowledge being good enough to take us through."