And Easterby's form as Scarlets skipper was instrumental in Llanelli qualifying with a 100% record from their pool, which included away victories over Toulouse, Ulster and London Irish.
Flankers Wallace and Easterby played prominent roles in Ireland securing a second successive Triple Crown during this season's RBS 6 Nations Championship, but their battle opposite each other on Friday night could have a significant bearing on the outcome.
Munster openside Wallace said: "Simon is such an unsung hero and is in the form of his life at the moment, so stopping him doing what he does best will be crucial to our chances of winning.
"He will be trying to get into our faces from the start - something he does so well - and you can imagine just how much he will relish doing that.
"Simon was outstanding in the (Six Nations) championship, and he just seems to get better and better.
"And while he will certainly be passing on a few tips about us to the Scarlets players, we also know all about him as a player, so it certainly promises to be an interesting battle.
"We have had a few words about it already, and it will all be friendly stuff - until we get out on the pitch. Then it will change, as both teams will be going full pelt at each other in what is going to be a massive game."
Munster, bidding to emulate Leicester's achievement in 2001 and 2002 by landing successive European titles, are without injured lock Paul O'Connell and full-back Shaun Payne. Mick O'Driscoll and Christian Cullen start as their respective deputies, with Ronan O'Gara captaining the side.
Llanelli, meanwhile, have been boosted by fly-half Stephen Jones' rapid recovery from a wrist problem and wing Mark Jones passing a fitness test after hurting his knee in training.
Recent Heineken Cup history suggests Llanelli have got it all to do though, with Munster unbeaten away in Europe for 18 months and the Scarlets losing home quarter-finals to Perpignan (2003) and Biarritz (2004).
But Easterby said: "We are a better side now than we were a couple of years ago, yet we need to start winning some big home games.
"There is more experience in our side now, and we have played some great stuff this season, so we are ready for them.
"Year in, year out, they (Munster) reach the knockout stages and are a benchmark for a lot of the teams. It doesn't get much harder than this."