The lineout was just about the only area where Ireland managed to dominate the French in last year's thumping 33-10 defeat in Paris and Les Bleus' lineout problems resurfaced in their Six Nations opener against Scotland.
But if the French lineout can be regarded as potential weakness, the same cannot be said of their scrum.
Despite giving up over a stone a man against the Scottish forwards on Saturday, the French pack vaporised their opponents' scrum, proving that size is no substitute for technique up front.
"The lineout is always very tricky against Ireland," said the Biarritz man who will win his 66th cap on Sunday.
"Ireland are one of the teams who steals the most opposition ball. So we've worked on it this week, especially because we struggled against Scotland.
"We lost a couple of balls through our own fault, and they managed to steal a couple as well.
"We weren't very effective at stealing their ball but it wasn't through lack of effort. It's always tricky in the first game, to play with guys who you've played against all season.
"We're not used to playing together, it's an area which needs lots of practice just to win your own ball, let alone stealing opposition ball.
"We've worked on it this week though, so hopefully we'll be able to steal a few balls.
"We'll have to be more accurate against Ireland.
"With the scrum it's different. Our front five are performing really well, and the front row is very solid.
"People have talked about our new scrum machine, but it's the players who make the difference.
"Against Scotland we were criticised after the game because we didn't use our scrum as a platform but we couldn't because nearly every time there was a scrum we got a penalty or a free kick.
"The most important thing is to score and make the opposition suffer, and if we do that through our scrummaging, all the better.
"We ended up getting a penalty try which allowed the forwards to really get into the match."
And while the 34-21 win over Scotland relieved some of the pressure on France, Harinordoquy knows they will have to tighten up their defence if they want to make it nine wins in their last ten games against Ireland.
France missed 25 tackles in Paris becoming the first tier one side to concede three tries to Scotland in four years.
"We were very disorganised against Scotland. We've had two big sessions on defence this week. We will have to be a lot more solid against Ireland.
"They tend to pass a little less out of the tackle but they are a stronger. We'll have to be very organised and a little more aggressive."