SCOTLAND have to rediscover their form today, something that is always harder than building on the momentum generated by a victory the week before. As we saw at the World Cup, when you have just won a game it becomes that much easier to prepare for the next one in a positive, self-confident frame of mind.

The Principality Stadium is a tough place for visiting teams to play in, and it has one of the best atmospheres in the world. The passion of the Welsh supporters is there to be felt, so it's very important that all our travelling support make themselves heard.

From Scotland’s point of view, the key to this match is coping with Wales’s physicality. The Welsh are not going to play a radically different game from anything we are used to: they will use Jamie Roberts and their forwards to try to stretch the Scottish defence as wide as possible, and then they will release their back line. Once they get over the gain line they can become extremely difficult to stop, so the key for our defence will be their first-up tackling, and matching Wales physically.

For me, the vital thing for players like Mark Bennett and Duncan Taylor is tackling low. It doesn’t matter how big the player running at you is - Roberts in the centre or George North on the wing - you’ve got to go low. We saw a couple of times against England that Scottish defenders tried to take Billy Vunipola high, and it didn’t work: he kept going and gained vital yards.

Mark’s a brave player and will stick his head in; Finn Russell too. Ideally we’ll have Duncan Taylor as well as John Hardie and John Barclay stopping Roberts, but Mark and Finn will have to make their tackles too.

On Scotland’s ball, I’d like to see more attacking edge than we had against England. There were times last week when we had chances to play the ball in different areas, but we just didn’t take them.

Contrast that with England, who took their opportunities well. They tried different things on occasion, such as the backhanded pass by Mako Vunipola that produced their second try, but on the whole it was just about being clinical. They had opportunities, and they took enough of them to win the game.

Obviously it was extremely disappointing to lose that match, but there were positive aspects within it that I’m sure Vern Cotter will have used this week to encourage the squad. Our set piece went really well against England, for example, so that’s one positive thing. And we competed well at the breakdown too, where John Barclay, for one, put in a really good individual performance - though I think that’s an area we’ll need to be even better in against Wales.

So this week in training will have been about remembering what went well - not only last week, but also in the World Cup. That will be Vern’s message. What makes Scotland a good team? What does he need to see out on the park?

I don’t think the Six Nations can be viewed in isolation, as an entirely separate event from other competitions. Yes, Scotland have now lost their last eight games in the Championship, but that’s stretching it back over the last three seasons, which in my view is counterproductive.

There was momentum at the World Cup, and even though we lost our last match there, to Australia, the team played so well that they can still use that to build morale. The ability is there: they just have to get it out.

And when it comes to the Six Nations, the only relevant fact is that we have lost our opening game. What happened a year or two years ago doesn’t count: it’s all about this season, and this game.

The same goes for Wales. They’ll probably have been happy to get a draw in Ireland, especially given the way they fought back, but they will be looking for improvements on their home turf.

Wales have built up a confidence in their own ability which it will be difficult to break. The key to doing so is to make them feel that, at least at times during the match, that they are not in control of the contest. The Principality is a big pitch, and we should use that to our advantage.

We’re not starting this game ten points down because we’ve lost our last eight games in the tournament. And we’re not starting ten points up because we did well at the World Cup. It’s a new game, a level playing field, and we’ve got to make sure we have every player firing when game time comes round. Then it’s all about the 80 minutes, and taking our opportunities.

I think the team today should be able to play rugby like they don’t have much to lose. I don’t mean throw caution to the wind, but they can certainly be adventurous. One of our real strengths is that we’ve got strike runners like Stuart Hogg and Tommy Seymour, and we’ve got to get them more involved.

And of course the more our players are on the ball and on the offensive, the more Wales will have to concentrate on their own defence. If Jamie Roberts makes 20 tackles in the game we should be absolutely delighted.

Al Kellock won 56 caps for Scotland between 2004 and 2013, and now works for Scottish Rugby in both a commercial and an ambassadorial role.