The pace-setters from the Guinness PRO12 and Aviva Premiership collide on Saturday with places in the squad bound for New Zealand this summer still available.
The last eight of Europe is being used by Warren Gatland to help finalise his selection plans before announcing his touring party on April 19, and the Aviva Stadium showdown sees several fascinating duels.
Leinster's Garry Ringrose, Devin Toner and Sean O'Brien are among those hoping to impress Gatland, while Elliot Daly, Danny Cipriani and James Haskell have the opportunity to argue their cases for Wasps.
"If you are a Lions coach you would certainly be looking at games like these where you have a Daly and a Ringrose, Joe Launchbury and Toner - the list goes on," senior coach Lancaster said.
"All these games leading into final selection for the Lions will have a part to play because of the quality of players on show.
"Deep down I think everyone knows a good performance keeps you in contention."
Possibly the most fascinating of all the head-to-heads will be Cipriani's battle of wits against Johnny Sexton.
Lancaster worked with Cipriani when he was head coach of England, eventually culling him from his World Cup squad, while Sexton is the Lions' Test fly-half elect.
"Danny is playing some great rugby at the moment. He has really benefited from Wasps' attacking philosophy and system," Lancaster said.
"With two other ball players in Jimmy Gopperth and Kurtley Beale in the backline it has freed him up, but he is still the guy who pulls the strings. He's a major weapon for Wasps.
"Johnny very much reminds me of Owen Farrell. He likes to lead the defensive line and he likes to take the ball to the line."
The Aviva Stadium was the setting for England's 13-9 defeat to Ireland less than a fortnight ago, a result that ended the quest to complete back-to-back Grand Slams and set a new world record for Test wins.
Many of the protagonists in action on that noisy Dublin night will be present on Saturday, but Lancaster insists it will have only a minor bearing on a clash between rivals who average over four tries scored in each match.
"It's similar in the sense that Nathan Hughes, Joe Launchbury and Elliot Daly all played, but they're two very different teams," Lancaster said.
"Wasps have a very unique way of playing and Leinster are quite different to Ireland.
"Clearly, the way Ireland slowed the momentum and stopped England's gain-line runners will be something we look at.
"We know that if we're loose with possession, Wasps can hurt you on the counter-attack like no other team can.
"We haven't referenced that game this week because it's a completely different context.
"Hopefully it's a dry day that's great for attacking rugby. I think it's going to be a brilliant occasion."
Lancaster has been offered a two-year contract extension by Leinster that will keep him in Dublin until 2019.
"It's not been finalised and confirmed yet but I'm certainly not looking at other options. I'm really enjoying my time here," Lancaster said.