There is an Olympic-sized physical examination coming the way of Leinster tomorrow.
"We've got to weather that storm," said Heaslip.
"My experience of playing against Castres, going there, is that they're quite a proud side at home, a tough side to break down at home and will come out the gates all guns blazing.
"If we stick to our game and bring the aggression and that relentless focus that we want at the breakdown and just basic carrying, our plays will cause problems," he added.
The captain also had a sample of praise for tight-head Michael Bent, a prop who has come in for a hail of criticism through no fault of his own since making his debut for Ireland in the Autumn of 2012 before he played for Leinster.
"Benty has gone really, really well in the games. He's a guy who has taken his chance and is putting it to Rossy," he said as Mike Ross and Marty Moore are sidelined by injury.
"To be honest, from tight-heads, I'm at the back of the scrum, I just want them to keep it somewhat steady, get the ball back and away we go, and then get around the field.
"Just carry when they have to, hit tackles when they have to and Benty's doing all of that and doing it pretty well".
A sound, steady platform is what the Leinster back row want to get onto the front-foot where Heaslip, Rhys Ruddock and that man Dominic Ryan can do damage.
"I've always spoken quite highly of Dippy," remarked Heaslip, in relation to Ryan.
"He's a serious athlete. In the gym, he's fairly impressive and he carries that through to the game, uses his strength and power really well.
"He goes around smashing lads in the tackle, hits rucks like a demon and is always around as a link player and, as we saw, he's no problem carrying the ball".