Easterby takes his side to the Twickenham Stoop on Saturday afternoon to take on the 2012 Aviva Premiership champions.
With French giants Clermont Auvergne and Racing Métro completing Pool 4, a lot rests on how the Scarlets start the competition.
And with the likes of Jonathan Davies and Liam Williams in his side, Easterby will be hoping they can inspire his side to begin the competition with a bang.
"Starting well is important. If you lose your first couple of games you're under pressure and if you win a couple, it's all on the other teams in the group," said the Scarlets boss.
"Winning your home games is vital - you don't play against these teams very often so you can surprise them which is what we've done in the past.
"There's often very little in it, sometimes you need a bit of luck but you have to have a bit of belief in the group. If you do that early on, you can build momentum in the group stages and sides can not want to play you after a couple of games."
With Racing Métro visiting Parc y Scarlets next weekend, it's undoubtedly a tough start to the competition for the west Wales outfit. But after seeing his side struggle in Europe last year, Easterby is adamant his side are more than capable of causing a shock.
"The European campaign last year was clearly not good enough," he said.
"We set our stall out in the first game and were more than competitive against Clermont away from home. Unfortunately, we went down to 14 men which isn't great at the best of times and we struggled to react.
"We then lost to Leinster and struggled for form in that period of the season. In Europe, you have to be right on your game and know how to win matches if you're not playing well."
Looking ahead to this season's competition though, Easterby is welcoming the chance to take on the best club sides from around Europe.
He added: "When you're a player you want to play against the best and it's the same as a coach. For me, the best thing other than playing is to coach against the best and at the moment, I'm fortunate to do that."