NARROW margins can make a massive difference. Even in Glasgow Warriors’ resounding 31-13 win over Munster in last year’s PRO12 final, as Peter Horne recalled this week, there were a couple of moments which could have changed the course of the contest. And, as he looked ahead to tomorrow’s semi-final in Connacht, and back to the defeat by the same side a fortnight ago, the centre suggested that apparently minor moments could again have a major effect on the outcome.

The Warriors can look back on that 14-7 result and honestly tell themselves that a couple of tweaks here and there were all that stood between winning and losing. They were a man down at the end, they made avoidable errors, and yet they were close to snatching a draw. They know they can do better, and, as Horne explained, they have belief in the players who have been over the course before.

“It comes down to who performs on the day, but we have over the last few years built up experience, and massive games like this come down to one or two little events,” the Scotland centre said. “Even in the final last year, we ran away with it at the end, but that game was settled on a couple of little instances, [for example] us holding up Paul O’Connell over the line. If they score there it’s a different game.

“We have to be more clinical this week - we let a lot of chances go last week. Naka [Leone Nakarawa] made a break straight from kick-off and we knocked it on, things like that. But if we can build pressure and score it’ll take care of itself. We’re looking for our experienced guys to step up and have a big game.”

What is more, they will need to do so from kick-off. Horne admitted that his team had begun slowly two weeks ago - a potentially fatal error against Connacht, who like to get off to a flying start then build momentum from there. “We’re trying to get out of the blocks quickly. They notoriously start games very well.

“They’re very difficult to get back once they get their tails up. We had a big emphasis on that, but we weren’t clinical enough - we should have come away from that opening spell with ten to 15 points, but we didn’t. We need to get into those positions and make the most of them this time.

“You never know, but I think we should have beaten them with 14. Right at the end there we were down in their 22. I’d like to think we’d have won with 15, but it’s hard to say, it’s a different game.

“It was tough. They put us under a lot of pressure, played really well and defended really well for periods of that game. I think we lost our shape a little and fell into the trap of slow ball, to slow ball, to slow ball.

“As we held on to the ball and went through a few phases there were chances, and it gives us a lot of hope, because if we have that extra guy we can put a bit of width on attack and have a crack. Especially in the second half, that last 20 minutes, we were sort of chasing rucks and lost our shape a bit, stopped playing. If we can have a good crack and keep 15 on the field we should be good.”

When the team is announced today, Horne should be partnered at centre by Mark Bennett. Alex Dunbar would probably have been preferred for his defensive solidity, but he has been ruled out for the rest of the season with the knee injury sustained at the Sportsground two weeks ago. Yet whoever is selected to start, every one of them will be prepared for one of the toughest assignments in recent seasons - one that they know, if they do themselves justice, is winnable.

“It sounds ridiculous, but we’re mad keen to get out there,” Horne added. “We’ve talked about having a bit more edge, more bite to our game.

“To go over and there and be the first club to win an away semi-final would be massive. That’ll be the aim for us. They’ve been so good at home, barely lost there, and they skelped Munster a few weeks ago.

“They’re playing really well. They’ll have the crowd behind them and their tails up. But it’s a great feeling going over there and trying to silence the crowd.”

Warriors winger Sean Lamont has replaced Tim Visser in the Scotland squad to tour Japan next month. The Harlequins back injured a knee in his club’s defeat by Montpellier in last week’s Challenge Cup final.