Ulster back row Roger Wilson says the battle between the forwards will be key to the outcome of Friday's Heineken Cup Pool 4 game against Northampton.
Wilson spent four years at the English Premiership club, before returning to his home province in the summer.
"Northampton have operated the same gameplan in recent years - it's basic but they do it very well," said Wilson.
"Their key weapons are their setpieces, their scrum and driving maul - very few teams can stop their forward power."
"They are a formidable side and the step up in intensity will be huge, but we must be ready for that.
"It will be a strange experience coming up against my former team but once I'm on the pitch it'll be down to business.
"I had four fantastic years at Northampton and have no regrets at all, but now I'm part of a team which is being touted as one of the best in Europe, so I'm happy."
Ireland winger Tommy Bowe was another player who returned to the Ravenhill ranks at the start of this season.
"We've had a god start to the season, but games don't come much bigger than this and two victories would really set us up to go through to the quarter-finals. The stakes are huge.
"They have a good pack, some very attacking runners and pose threats all over the pitch, but we are more than capable of going there and getting a win.
"The five day turnaround from the Scarlets match is not ideal but we have recovered well and had some good training sessions," explained the former Ospreys player.
Second row Dan Tuohy confirmed that the Irish province is preparing for "a huge physical battle".
"They can play a bit behind the scrum but their bread and butter is a massive physical battle.
"Stephen Ferris is injured and would be a loss to any team in world rugby, he's a big game player, but Iain Henderson has probably surpassed everyone's expectations and is a more than competent replacement - we have that strength in depth," said the Irish international.
Ulster are currently top of Pool 4 with nine points, three ahead of second-placed Northampton.
Mark Anscombe's side are unbeaten in their 12 competitive matches so far this season.