What a difference two years makes.

In round five of the Champions Cup in 2016, a Leinster side with nothing to play following a dismal European campaign decided to freshen up their team.

Leo Cullen, negotiating a difficult first season at the helm which included record European defeats, handed Champions Cup debuts to Garry Ringrose, Luke McGrath, Peter Dooley, James Tracy, Tadhg Furlong and Ross Molony.

All six performed admirably in a 25-11 win, with second row Molony scooping man-of-the-match as the dark cloud of 2015/16 had a clear silver lining.

Garry Ringrose on his European debut against Bath in 2016

Twenty-four months later and McGrath and Furlong will start this year’s round five clash at home to Glasgow, while injury prevents Ringrose from making it three.

The European landscape is quite different now; Leinster are one of only three sides unbeaten (along with Munster and Clermont) in the competition and Cullen has again thrown caution to the wind.

Jordan Larmour has delivered a level of performance in his 12 outings to date which belies his age in what will be his first Champions Cup start, with Rob Kearney forced to make do with a place on the bench.

On the wing, further X-Factor will be on show when attack-minded James Lowe make his first appearance in the competition.

Differing circumstances, but a similar positive approach from Cullen.

"We have discussed this week this game two years ago when Leinster played against Bath and the teams were announced," he recalls.

"I remember hearing and reading comments how I was disrespecting the competition by picking some players for their first starts in Europe. Some of those guys went on to do really well in that game."

Larmour is enjoying a rich vein of form for Leinster 

Home-grown Larmour has been making headlines since his introduction this season, with two mesmerising tries over the festive period lighting up the early season.

"If he could score a try like he did at Thomond Park again early in the game that would be helpful," Cullen grins. "And similar to what he did against Ulster as well."

The head coach is fulsome in his praises of the 20-year-old and expects a cool temperament to stand the St Andrew’s prodigy well.

"He's been excellent. Jordan is very competitive naturally and wants to get better. It's a pleasure to coach those type of players."

"He's a very exciting talent and offers a lot to the attack of the team. He's gone about his business well and look forward to see how he goes.

"Jordan’s very steady in his approach and he's working away at a number of things. He's a young player coming into the team, of course he's got things to get better at. But he's starting off in a pretty good place.

"He's been excellent. He comes in and is very competitive naturally and wants to get better. It's a pleasure to coach those type of players."

Lowe too has had the Leinster supporters off their feet in his short career to date in Irish rugby. The former Chiefs man has scored two tries in three Pro14 outings, with a number of scintillating breaks and off-loads also added to the mix.

While Cullen admits that there are defensive tweaks that may need to be made for a player who has had a busy work load, he is eagerly looking forward to his first taste of European action.

"He’s had a lot of games coming in here so we were very cautious about how we manage him. It’s not just about the here and the now," he insisted.

"James has worked hard to try and get up to speed. It’s always difficult joining a group that are well established over the course of a season.

There are definitely areas we felt James needed to work on, but he’s working away and he’s been exciting in the games he has played. 

"Hopefully he will be exciting again on Sunday."

Listen to live and exclusive radio commentary of Ulster v La Rochelle (Saturday 1pm) and Racing v Munster (Sunday 3.15pm) on RTÉ Radio 1.