Leinster head coach Leo Cullen says he has full faith in Ross Byrne to steer the province for the rest of the season, as they continue their push for a URC and European double.
Captain Johnny Sexton has been ruled out for the rest of the club season after undergoing surgery on a groin injury this week, with Byrne set to lead the attack from the 10 shirt at the business end of this campaign, starting with Saturday's Heineken Champions Cup Round of 16 meeting with Ulster at a sold-out Aviva Stadium (5.30pm).
The 27-year-old has been in career-best form this season, returning to the Irish squad and playing in all five Six Nations games, while he also started each of Leinster's Champions Cup pool games in Sexton's absence, kicking 16 conversions.
Barring a miracle recovery between now and the end of May, Sexton looks certain to miss the rest of the season, but Cullen says he will still have a major role to play as captain of the group.
"He was down at training yesterday, on his crutches. Obviously, he had his surgery on Tuesday," the head coach said.
"Johnny will be influential, hopefully for the rest of the season. At the moment it's just week-on-week, isn't it?
"Hopefully Johnny will play a role, for the moment it's all about the here and the now so we're not really looking past tomorrow, so it's just geared up towards this game.
"It's part and parcel of the game, isn't it? We're lucky in terms of the squad we have."
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Byrne is no stranger to filling in for Sexton in big games, and did so when Leinster and Ulster locked horns in the quarter-final four years ago, kicking 16 points in the 21-18 victory.
"Johnny has gone off and had his surgery which is likely going to rule him out for the rest of the season, we all know that now. For him, he's just got to deal with the rehab part and turn his attention to whatever that process looks like for him.
"For the rest of the guys, they just kick on, into gear, and it's an opportunity for someone else to step in and obviously Ross wears the 10 shirt this week and he's been excellent throughout all the season and past seasons as well.
"There's a huge amount of confidence there so we just look forward and it's an opportunity for someone else, that's the way I always look at it."
Cullen has made 13 changes to his starting XV from the side that were held 22-22 by the Stormers a week ago, with Jordan Larmour and Ross Molony the only two to keep their places in the side.
Notably, Garry Ringrose and Caelan Doris both miss out, having gone through the graduated return to play protocols this week.
Doris has come through the protocols but misses out on selection having been ill during the week, while he says Ringrose will be available to play next week, should Leinster secure a place in the quarter-final.
The province are heavy favourites to move past Ulster and book a last-8 tie with either Leicester Tigers or Edinburgh, having beaten Dan McFarland's side in each of their two meetings in the URC this season.
But Cullen says their neighbours have consistently caused problems for their defence.
"They're a very efficient team, the way they play, and because they know us well so they've a really good understanding of what we're trying to do," he said.
"They've come out and said it plenty of times in recent years, their desire to win trophies, so they're clearly an ambitious, hungry bunch to do well. So we need to respect that.
"The game in the RDS was unusual, there was the red card and we'd a very slow start to that game so we need to learn the lessons from that first 20 minutes so we're not in that situation where we have to chase the game to that extent.
"On the flip side of that, the game up in Ravenhill earlier in the season, we started the game well that day, conditions were very difficult that day, they came back into the game strong towards the end. I remember Charlie Ngatai made that try-saving tackle in the corner and sometimes it comes down to those big moments in the game.
"For us, we've tried to do everything we possibly can this week so we don't start the game as slowly as we did the last day against them.
"But Ulster won't make it easy, they have a certain way they do things - a strong kicking game off 9, they chase hard, they defend well, good around the contact area, they've got a good bit of pace out of the wings as well - [Jacob] Stockdale and [Robert] Baloucoune, [Michael] Lowry, the three of them - they have some dangerous x-factor players.
"We just need to make sure they're queued up the whole time and some of the threats that they do have and try to impose ourselves on the game as well as we possibly can the whole time as well."
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