The 32-year-old suffered a shoulder injury in last weekend’s 37-28 victory over Edinburgh in Dublin and is likely to be replaced by Malcolm O’Kelly, who will retire at the end of the campaign.

Cheika was boosted by the news that Gordon D’Arcy should have recovered from a head injury in time to take to the field at the RDS, while Jonathan Sexton and Shane Jennings should also make the starting XV.

And if Leinster register their third successive triumph over Munster this weekend, Cheika is backing Cullen to return in time for the showpiece final.

“He [Leo] just got a bad trauma to his shoulder. He won’t be available for this match but we’d be hopeful that his season is not over yet,” said Cheika.

“I’d say Johnny Sexton is going to be alright. He’s just trained now. He probably could have edged it [in playing] last week but we decided not to.

“Every ruck, every ball is going to be contested fiercely [against Munster]. You saw the way they played against Cardiff; they fought for every ball on the ground, contested everything.

“It wasn’t pretty but they really showed their character in fighting for every ball. If there is one thing that we are well aware of, it is we are going to have to be at our most physical if we want to win the game.”