Jonathan Davies: Wales hail their classy clubs, but Gatland has plenty of work to do

The prospect of the Ospreys and Cardiff Blues winning their way through to the Heineken Cup quarter-finals today has got Wales buzzing. It would be the first time since 2001 that two Welsh teams have reached the knockout stage.

But while it would be a big boost for Welsh rugby, those who see it as predicting a shock for England in the Six Nations opener at Twickenham in two weeks' time are getting a little ahead of themselves. It would definitely be an encouragement but that's all, and no one should underestimate the size of the task facing Warren Gatland and his new coaches, Shaun Edwards and Rob Howley.

For a start, the force that has taken the Ospreys and the Blues into these thrilling climaxes of the pool stages is due more to Kiwi than Welsh influences. A healthy number of Welshmen are hitting form at the right time, but the most telling contributions have come from New Zealanders. For the Ospreys, Justin Marshall, Marty Holah and Filo Tiatia have been inspirational. For the Blues, skipper Xavier Rush and Paul Tito have galvanised the Cardiff pack with their ball-carrying abilities, while Ben Blair's form in the backs has been consistently excellent.

Their performances have had an effect on those around them. The new Welsh captain, Ryan Jones, has had the platform to return from a long injury lay-off and quickly recapture his international form as a surging back-rower for the Ospreys.

At the Blues, I'm sure the exciting form of Martyn Williams helped him to respond positivelyto Gatland's persuasion to come out of international retirement. This is a great coup for Gatland and a sign that his approach is working already if he can tempt an old pro back into action.

Today, Gatland will be examining how his charges cope with the death-or-glory stages of the Heineken Cup. The Ospreys have only the slimmest hope of topping Pool Two, but a win in Bourgoin should see them through as one of the best runners-up. Bourgoin have nothing to play for but their pride but that's enough of an incentive, especially at home. They certainly won't roll over.

But at their best the Ospreys can beat anyone in this competition, and their tremendous performance in beating Gloucester last weekend will have their confidence soaring. Yet their domination should have led to more tries. The Ospreys' backs are not yet firing on all cylinders. James Hook and Gavin Henson have been improving, but communication between them is still well short of what it should be, and I look forward to an improvement in this department today. I favour the Ospreys' chances ahead of those of the Blues, who have a very tough proposition at Bristol. The Blues have been playing very well but this will be their hardest fixture so far – even harder than Stade Français, which is saying something.

Bristol are so hard to beat at home. Cardiff at least know that a win will guarantee them leading the pool, while the home side's own chances of going through depend on them scoring four tries and gaining a bonus point. By no means do I write Cardiff off, but they will need to produce their mightiest performance yet.

Whatever happens to them today, members of the Wales squad can expect a testing time in the next two weeks when Edwards takes up his coaching duties. His priority will be to shore up their defence in double-quick time.

The romantic view of Wales as scorers of exciting tries doesn't wash if they can't defend properly. If you can't defend then you will never win. Some players are in for a rude awakening while Shaun hammers that message across.