Donal Lenihan and Bernard Jackman believe Jacques Nienaber's addition to the Leinster coaching set-up can lead to greater success for the province, with the former referring to him as the "missing ingredient".
Leinster have suffered near misses in the BKT United Rugby Championship and the Champions Cup in recent seasons, beaten finalists in the latter and exiting the URC at the semi-finals stage in each of the last two campaigns.
The Rugby World Cup-winning head coach, who served as defence coach under Rassie Erasmus at Munster between 2016 and 2017, returns to Irish soil as former boss assumes the mantle of Springboks head coach.
"He's the right man, in the right place, at the right time," Lenihan told viewers of RTÉ's Against The Head.
"He's also coming in, while he's been with South Africa and done a brilliant job over the past four or five years, he also knows the DNA of Leinster. He knows it from the outside.
"He can go in there and talk about 'this is how you are perceived by everybody else, this is how your neighbours down the road saw you'.
"They've lacked something. They have the players. Is there 18 or 19 to come back in from the Ireland World Cup squad? But just that last 5%.
"He was also the king of defence when he was in Munster. That was his primary area of activity. Also, if you were to look back at one of the key elements of South Africa winning the World Cup, I think they conceded only seven tries throughout the whole tournament. His defence was outstanding.
"We know their attacking quality, we know the sum of their parts. I think with that extra 5% to get over the line, allied with an even stronger defence, he could well be the missing ingredient."
Jackman also backed Nienaber to prove a defining part in Leinster's immediate future, saying: "They have the talent. There's no doubt they have the most talent in terms of depth in Ireland.
"Nienaber is going to come into a team who are desperate for him.
"They had a lot of belief in Stuart Lancaster but obviously that that journey is over and they just want to get across the line. They just want to be champions of Europe, certainly at a minimum to be winning URCs.
"They slipped up last year and didn't have anything to show for it, despite playing great rugby all year, but they know they are going to be judged on Champions Cups and URCs.
"He was well respected in Munster with Rassie, but what he's done since, you'd have to be envious of watching what he's done with the Springboks, to go back to back. He's a winner."
Watch Ulster v Munster in the URC on Friday from 7pm on RTÉ2 and RTÉ Player, follow a live blog on RTÉ.ie/Sport and the RTÉ News app and listen to live commentary on RTÉ Radio 1 Extra.
Watch Dragons v Leinster in the URC on Sunday from 1pm on RTÉ One and RTÉ Player.
