Mercey and Co head to Adams Park on Saturday aiming to build on the stunning 18-9 success secured at the Aviva Stadium last weekend.
But they know they won’t have it all their own way against a Wasps side currently sitting seventh in the Aviva Premiership standings.
And tighthead prop Mercey is well aware of what a potentially tricky fixture this could prove for his side.
“It’s a potential big banana skin for us,” he said. “We’ve got to treat this week with the same respect as we treated last week and just rely on the systems.
“Ultimately, what we focused on last week was a performance and we’ve just got to take that into this weekend and show respect for Wasps for being the good side they are.”
But Saints will undoubtedly take plenty of belief from the way they delivered in Dublin last time out.
And Mercey knows that standard of that display must be maintained in the coming weeks, with games against Bath and Harlequins coming hot on the heels of the Wasps clash.
“That’s got to be the minimum standard we take forward,” he said. “In the back of everyone’s mind has got to be the week before, when we lost to Leinster (40-7 at Franklin’s Gardens).
“If we don’t start the game right, that can certainly happen.
“Every team in the Premiership has got good players and the ability to do what Leinster did to us.
“It’s just the focus we need to get and build on last week’s performance.”