Leinster head coach Leo Cullen has made five changes to his starting line-up as he aims to guide his new charges to a third consecutive Guinness Pro12 triumph against the Scarlets this evening (7.35pm kick-off).

The departure of Mike McCarthy and Rhys Ruddock to the Irish camp (in place of injured Munster duo Paul O’Connell and Peter O’Mahony) has forced Cullen to make significant alterations to his pack. Following a late cameo against Newport Gwent Dragons last Saturday week, Ross Byrne is handed his first start for the Blues at out-half.

He will be joined at half-back by the experienced Isaac Boss, who will be making his fourth appearance of the season in Parc y Scarlets tonight, and is anticipating a tough encounter against the current table-toppers (who hand a debut to Canadian World Cup star DTH van der Merwe).

“Scarlets has always been a tough place for us to go and play, even when we’re both full strength. They play a good brand of rugby and they’ve got a really good record at home. They’ve started the season really well, but it’s a good chance for us to measure ourselves,” Boss remarked on Monday.

“They’re at the top of the table, and if we can actually topple them it’s a big feat and it means a lot for us and our season, and it probably separates the men from the boys a little bit.”

With no decision made on a potential replacement for Jared Payne just yet, Joe Schmidt and his coaching team may cast a glance on the proceedings in Llanelli, which is a relatively short distance from Ireland’s Welsh training base. Although they play in different positions to the Ulster man, Fergus McFadden and Noel Reid have been mentioned as possible candidates for a late call-up. They retain their places in the back line alongside Isa Nacewa, Garry Ringrose and Boss, but with Ben Te’o currently nursing a minor injury, Colm O’Shea partners Clontarf club-mate Noel Reid in the centre. Bryan Byrne replaces Aaron Dundon in the front-row – where Michael Bent and Marty Moore will again fill the prop positions – while Tom Denton and Dan Leavy will deputise for McCarthy and Ruddock.

Now 19 players are away an international duty, it is no surprise there is an inexperienced look to Leinster’s replacements bench, with Wexford native Tony Ryan featuring in a match-day squad for the first time.

LEINSTER:

I Nacewa; F McFadden, C O’Shea, N Reid, G Ringrose; R Byrne, I Boss; M Bent, B Byrne, M Moore; R Molony, T Denton; D Ryan, J van der Flier, D Leavy.

Replacements:

J Tracy, P Dooley, J Hagan, T Beirne, T Ryan, L McGrath, C Marsh, M McGrath.

SCARLETS:

A Thomas; H Parkes, R King, G Owen, DTH van der Merwe; S Shingler, A Davies; R Evans, K Myhill, P Edwards; G Earle, T Price; A Shingler, J Davies, J Barclay.

Replacements:

R Elias, P John, W Taylor, T Phillips, J Condy, R Williams, D Jones, T Williams.