THIS is it for Edinburgh. Either they kick-start their season tonight against La Rochelle or it expires prematurely.

Ninth in the PRO12 and with no real prospect of finishing higher, they have been short of confidence recently, at times appearing as if they were just marking time until the summer when Richard Cockerill takes over as head coach. But while their league form has been dismal, they have saved their best performances for Europe, and have to hope that they can find it in themselves to get back to their best in this Challenge Cup quarter-final.

It will not be easy. La Rochelle may lack the glamour and the big names that some other French clubs can boast, but they have opened up an 11-point lead in the Top 14 and, with just a handful of games remaining, look set to claim the title.

The visitors’ recent form is thus very different to Edinburgh’s, and so too are aspects of their overall approach. They have a huge pack, for instance, in contrast to the Scottish side’s lighter, more mobile forwards. And, while Duncan Hodge’s team like to have some sort of rational pattern to their performance, La Rochelle thrive on unstructured play.

That is an awkward combination for Hodge to combat, as he wants his team to move play around, away from the French heavy brigade, but cannot afford to let everything become too loose. To succeed, Edinburgh will need to perform with a purpose they have lacked of late, and choose wisely between keeping things tight and steering possession away from the La Rochelle pack.

“It's just getting that balance between being nice and structured and get in position to pull them around a bit,” Hodge said yesterday. “They like unstructured as well, but their forwards are big, heavy men. We don't want to be running into them, but there are times in a game of rugby when you have to - look at the Six Nations, it's a physical game at times.

“We're going to have to take them on as well. Their backs are good defenders and it's not going to be easy to just run around them.”

At their best, Edinburgh are more than capable of running around some teams, but some of their most influential players are missing for this one, leaving the squad short of experience and cover. Props Alasdair Dickinson and Willem Nel and openside flanker John Hardie are among the longer-term absentees, while two more Scotland forwards, Allan Dell and Ben Toolis, have joined them on the sidelines for this game because of injury. Anton Bresler and Grant Gilchrist form the second-row partnership in Toolis’s absence, while Murray McCallum moves across the front row to deputise for Dell at loosehead.

But all teams suffer injuries, and, while Edinburgh’s resources are stretched, they still have players capable of making a big impact. The back row of Bill Mata, Hamish Watson and Cornell du Preez is pretty impressive, for example, while behind the pack the likes of Blair Kinghorn and Damien Kinghorn are adept at counter-attacking from deep. The key to victory has to be shrugging off that collective lack of confidence which has afflicted them lately, and playing with the panache they showed in their pool wins over Harlequins and Stade Francais - although as Hodge explained, such a speedy transformation is by no means easy.

“You look at the last couple of games it’s been a mistake by one player, a mistake by another,” he said. “If it hasn’t been the attack it’s been the defence. That’s the frustrating thing - it would be simple if it was one area and we could say we can fix that.

“Last week [when Edinburgh lost 26-10 to the Scarlets] there was not just one area. There were a few defensive errors; a couple of dropped balls.

“It’s a combination. One sparks another. We’re clear what we want to do - we just have to execute it and get a real fast start to get a foothold.

“We all know there’s pressure going into the game: we don’t get many European quarter-finals at home against quality sides. There’s plenty of pressure riding on this game. We all know and accept that. There will be moments that will be tough and we have to keep our clarity of thought, which we didn’t do last week.”

Sometimes, of course, big games produce the right kind of pressure. Back at Murrayfield, and in a one-off European tie as opposed to another run-of-the-mill league match, Edinburgh can rise to the occasion.

“We’re playing against fresh opposition,” as Hodge added. “They play in a different league with a different style. Even a quarter-final back at Murrayfield is fresh stimulus. It’s a good thing for us at this moment in time.”

Edinburgh (v La Rochelle at BT Murrayfield, tonight, 8pm): B Kinghorn; D Hoyland, C Dean, P Burleigh, T Brown; J Tovey, S Hidalgo-Clyne; M McCallum, R Ford, S Berghan, A Bresler, G Gilchrist, V Mata, H Watson, C du Preez. Substitutes: S McInally, K Whyte, K Bryce, F McKenzie, V Fihaki, N Fowles, D Weir, G Bryce.

La Rochelle: K Murimurivalu; S Barry, P Jordaan, P Aguillon, E Roudil; Z Holmes, A Retiere; M Corbel, J Maurouard, M Boughanmi, J Eaton, M Tanguy, R Sazy, B Veivuke, K Gourdon. Substitutes: H Forbes, D Priso, L Kaulashvili, J Nailiko, V Vito, A Bales, B James, B Nobles.