VIDEO: Leinster a different team in 2018
He was speaking after helping Leinster book their place in the Bilbao showdown with a thumping defeat of Scarlets at Lansdowne Road on Saturday.
Munster, Leinster's bitter Irish rivals, face French club Racing 92 – Sexton's former side – in Sunday's second semifinal in Bordeaux.
But the Leinster captain, who scored 18 of the Irish province's points in a resounding 38-16 win over Scarlets, jokingly dismissed the enquiry.
"Do you expect me to answer that?" he replied, with a laugh.
"I'll just give whoever [qualifies] a team talk now! They're both quality teams, no matter who plays it's going to be a very tough game."
Flyhalf Sexton, the on-field tactical mastermind as Ireland completed a Six Nations Grand Slam earlier this season, added: "Racing was champions a couple of years ago in France and Munster, if we play against Munster it will be a very special game for all of us.
"Racing more so for me than the rest of us. It's going to be a tough game no matter who we play."
It is likely to be tougher than Saturday's semi-final, where Leinster dismantled a Scarlets side who headed across from Wales buoyed by having beaten the same opponents in last season's Pro 12 semi-final in Dublin.
This time around, three-times European champions Leinster ruthlessly dominated from start to finish.
"I said on Friday that we'd find out in the game if we learnt from last year's defeat, and we did," said Sexton, one of five Leinster try-scorers on Saturday that also included former Wallaby back-row Scott Fardy.
"We looked like a different team to the one that played in that semi-final last year," the Ireland playmaker added.
"We are, in many ways – a lot of players who didn't play last year made a big difference [on Saturday]."
"We've been underdogs and won, we've been favourites and lost. I don't think we're that much better than Scarlets, we just took our chances."
Scarlets coach Wayne Pivac had no complaints regarding a result that ended the west Wales side's hopes of a first appearance in European club rugby union's showpiece final in emphatic fashion.
"Leinster played very, very, well, as hard as it is to take, you have to say they were very good," conceded Pivac, long touted to succeed fellow New Zealander Warren Gatland as coach of Wales.
"They were the better side, it was a mix of how well they played and how well we didn't play," he added.
Both Pivac and Scarlets captain Ken Owens were impressed by Leinster's clinical game-plan.
"They were very direct, they looked after the ball in contact, and once they were into our 22 they were very clinical," Pivac said. "In the game of feet and inches, they won."
Wales hooker Owens added: "They are one of, if not the best side around at executing a game plan. You could see they learnt lessons from the defeat last year…they dominated the game pretty much.
"They were more direct, similar to how Ireland play. They got quick ball, they had a ball carrier plus two (players) at the rucks."
This was Scarlets' first European semi-final since 2007 and, despite this hammering, Pivac backed them to mount another strong challenge next season.
"We did a lot to get here, let's not forget that – we're in the top four in Europe, but we have to keep improving," he said.