IT may be only one match but the psychological impact of Glasgow's game at Cardiff this evening could be huge.

After it comes a change of pace as teams switch into European mode and have the chance to assess where they stand in the league after their first batch of games.

As John Barclay, the flanker, points out, tonight's game makes all the difference between the team believing they are on track and feeling there is work still to be done.

"If we go into the Heineken with four wins from six games and a couple of bonus points as well, that would be pretty good," he said. "Obviously we would like to have won the Scarlets game at home but four wins after six games would be a good place to be, so we have to make sure we put in a good shift against Cardiff."

Defeat, would leave them with a 50-50 record from their first batch of matches and, while there is still a lingering frustration at the way they were beaten in their first match at Scotstoun, 18 or 19 points from six matches would represent an advance on last season, when the loss of the team's international players to the Rugby World Cup contributed to a shaky start.

That loss of so many key players to the national cause makes direct comparisons hard, but they are ahead of where they were at this stage a year ago on both tries and points they have claimed in the league table.

For Barclay, the key demand is finding that game where the attack clicks, and a team that has long been able to depend on its defence will be able to start putting teams away in the style they want.

"Our defence has been pretty good and we have played some good stuff in attack," Barclay said.

"If you have your defence sorted, that goes a long way. If teams can't score against you it makes it very hard to beat you. You can get away with defending very well and waiting for the attack to click; attack is harder than defence."

Barclay is back in his favourite role at openside flanker after rediscovering his appetite for the game while playing right across the back row at the tail end of last season and on Scotland's summer tour. After a couple of earlier games there this season, he is starting to feel that he is getting back to his best, though an inexperienced Italian referee could have the final say on how effective he is allowed to be.

"It is always nice to silence a home crowd," he said. "It is a while since I played at the Arms Park – it is a nice old ground – so I am looking forward to the game. Cardiff have not had that good a run so there may be a little doubt there, though away from home it doesn't change; you have to do the basics well and you've got to defend well.

"I still see myself as an openside; that is where I want to play. I enjoy it and really felt good in the last game I played there, the sharpest I have for a while. I am looking forward to it."