Both sides are in semi final action against Clermont and Saracens respectively
By the time this weekend is over, we could be set for an all Irish European Rugby Champions Cup final, if all goes well for Munster and Leinster.
But both both sides face tough challenges against Saracens and Clermont Auvergne respectively in the semi finals on Saturday and Sunday.
Leinster and Ireland great Brian O'Driscoll joined Off The Ball to look ahead to both semi finals and started off by picking out key factors from the Sunday fixture between Leinster and Clermont at Matmut Stadium.
Long time Clermont wing and centre Aurelien Rougerie is now 36 and has been named to start at outside centre. And while O'Driscoll cites the former France international's wealth of experience, he feels the younger Garry Ringrose could gain an advantage over the veteran in what could be a high tempo clash between the teams.
"There's no doubt, the juice has gone in his legs. That happens for all outside backs and usually before 36. He's not in their starting team and I'd be excited if I were Garry Ringrose, playing against someone who is 14 years older than him," said O'Driscoll.
"[Rougerie] has a wealth of experience but the zip is a huge part on a dry day on a hard pitch. It's 100ths of a second, it's reaction time."
He added that, "Garry Ringrose should know that in advance and take full advantage of it."
O'Driscoll feels the start could prove key for Leinster in France against a Clermont team that has often missed out on glory at the final or penultimate hurdle at home and in Europe.
Meanwhile, Munster face reigning English and European champions Saracens on Saturday and Ireland scrum half Conor Murray is unavailable due to injury.
O'Driscoll feels that it would be better to have a replacement scrum half on the bench, just in case, to cover Duncan Williams who will start at 9.
On members of the starting team, he spoke about how impressed he has been by Rory Scannell, who will start at 12, and that his rise to the starting XV shows how valued he is by the province.