Nick Williams' absence hit Ulster hard during that damaging Six Nations spell.
The burly New Zealander – 6ft 3ins and 18st 12lbs of raw back row power – suffered medial ligament damage to his left knee in Ulster's 23-6 Heineken Cup win over Glasgow at Ravenhill on January 11 and missed the next nine weeks as a result.
While he felt the pain at a personal level, Ulster felt it too in a different way; in his absence they lost to Ospreys and Glasgow and drew against Treviso.
The two things Ulster missed most during the 29-year-old Auckland-born former Junior All Black's time out were his skill as a carrier and his ability as a finisher.
No-one got close to providing the things he has contributed to Ulster's cause since enlisting last summer, witness seven tries in 16 outings.
Originally seen as providing back-up for Roger Wilson, instead Williams has managed to work his way to the head of the queue for the No 8 berth.
He doesn't see it that way, of course. In his view it's a case of horses for courses, depending on the game plan and the nature of the opposition.
"The good thing about Ulster is that we can play different types of games with different players included at different times. It's all about the game plan we want to play," he explains.
"Roger is a great No 8 and he brings different things to the game. There have been games when he has been preferred at eight so I wouldn't say that I'm first choice."
He has packed down on the blindside flank on occasions, too, but he sidesteps the question of which role he prefers by saying: "At the end of the day it's just a number on your back. The two positions aren't that much different. Being on the paddock, rather than the number I have, is what matters most."
Impressively strong on the field, he is an admirably modest man off it. Reminded of just how much Ulster missed his ground-making surges and ball-carrying excellence he looks embarrassed, shrugging and smiling.
"It's an aspect of the game that I like to pride myself on," he says. "There are a lot of things you can work on and build up and for me this is one of them.
"I enjoy carrying the ball, but it wouldn't happen if it wasn't for the things the other guys are doing to make it possible," he says.
He feels fully recovered from that knee injury and is delighted to be playing again.
"The lungs were feeling it a bit after last week but that's normal when you haven't been playing for a while," says the man who played the second 40 minutes against Edinburgh.
"The leg feels really strong so I'm just looking forward to getting on the paddock again and getting a few more minutes under my belt," he replies when asked about his recent injury.
The challenge presented by tonight's hosts at the RDS promises to be awesome. Leinster in their own back yard? They don't come any harder. But Williams knows what winning would mean to Ulster.
"Rory (Best) was telling me that the last time we won down in Dublin was 1999 so that's a long time," he says. "Us foreigners have bought into the whole rivalry thing. We know about that, we understand it.
"It's the same where we come from. Back home, when Auckland play Crusaders, that's huge too because they're big rivals. The only difference is that when they play it isn't snowing!
"So we've bought into the rivalry, no worries. I played against Leinster when we beat them at Ravenhill just before Christmas and that was special. We'd settle for a similar result this time."