And Cullen did not rule out the Wallaby playing in the back row if it was required, although he stressed he has been signed as a lock.
Fardy has played 39 times for Australia since his debut in 2013 and Cullen believes he will add massively to the current Leinster crop.
“At the start of the week, there was the announcement about a lot of young academy players progressing into the senior team and if you think of what the model is here at Leinster, of committing so many resources to the academy in trying to produce good young players, to get someone like Scott Fardy into the group who has 39 Tests, a lot of Super Rugby experience... he’s been around and played in Japan as well.
“The level of experience he can bring to the group and add to the environment, I had some good discussions with him and he can really add to the group on a much broader scale than just on the field.”
Cullen’s first priority this evening is to extend their five-match winning run when they take on another side who are in a rich vein of form, with Scarlets coming to the RDS buoyed by their comeback win over Munster in Thomond.
Leinster have won 12 of their 13 home matches against Scarlets in the league, with their only defeat coming in 2007-08. Cullen has made just three changes to the side that hammered Dragons 54-22 at Rodney Parade . There is just one change the back-line where scrum-half Luke McGrath comes in to replace Jamison Gibson-Park.
There are two further changes in the pack, with Richardt Strauss remaining on as hooker and he captains the side for the first time at the RDS. Second-row Hayden Triggs scored a try off the bench against Dragons last weekend, and he comes in from the start.
Dan Leavy starts at openside flanker instead of Peadar Timmins – Leavy was the 24th man at Rodney Parade. And although Fardy’s signing could impinge on the game-time for players like Leavy and Timmins, Cullen says that won’t be a problem.
“We’ve basically signed him as a second-row so that’s where Scott will primarily will, or will be considered to play. Obviously, depending on any given day things and plans change.”
And Cullen hasn’t ruled out the possibility of signing winger James Lowe from the Chiefs after media reports emerged that he may be their next target.
“There’s a bit of truth in some of them (rumours) and no truth in others. We will see. I’m sure there will be an announcement at some point. We’re in talks with lots of players, all in due course.”
J Carbery; A Byrne, Z Kirchnerm, N Reid, F McFadden; R Byrne, L McGrath; P Dooley, R Strauss, M Bent; R Molony, H Triggs; R Ruddock, D Leavy, J Conan.
B Byrne, E Byrne, M Ross, M McCarthy, M Deegan, J Gibson-Park, T Daly, B Daly.
J McNicholl; T Williams, S Hughes, H Parkes, DTH van der Merwe; D Jones, J Evans; W Jones, R Elias, W Kruger; T Price, T Beirne; A Shingler, J Davies, W Boyde.
D Hughes, L Garrett, N Thomas, R Bernardo, M Allen, D Smith, A Thomas, I Nicholas.