The problem with the play-off final is someone has to lose. A whole season boils down to 90 minutes - or in my case, 120 minutes and penalties when I took Barnsley to Wembley four years ago - and this Saturday afternoon one set of players are going to be sat in the dressing room after the match reflecting on what might have been.

Of course, the final is an amazing occasion. My experience with Barnsley was ultimately a great one because we beat Swansea on penalties in the shootout but even as we were celebrating our promotion, I remember thinking at the time how tough it must have been on the Swansea players and coaching staff and this year's Final between Millwall and Swansea will once again produce that heady mixture of triumph and tears.

It's why we all love the play-off final and why it's so often so compelling to watch.

Both teams go into the final in terrific form. Swindon have had a superb second half to the season and showed a lot of nerve and character to beat Charlton on penalties. They could have folded after going two down in the second leg at the Valley but had the mental strength to battle back while Millwall were fantastic in their semi against Huddersfield.

Which all means it's hard to choose between the two of them.

People often ask me what's the secret to winning a play-off final. Obviously, it's far from an exact science but if I learned one thing with Barnsley, it was to try and keep the build-up to the game as low key as possible.

Playing at Wembley can be a massive culture shock to players who are used to smaller stadia. There's nothing you can do about the atmosphere, the noise and the expectation when they get out onto the pitch but you can keep things relaxed and routine in the days before the game.

For me, it's all about trying to ensure the players don't freeze on the day so before Barnsley played Swansea, I prepared the players in exactly the same way I did for any other game. We didn't talk about Wembley, we didn't talk in terms of a final and we didn't discuss promotion. Of course, we talked about Swansea but it was as if we were playing them on a cold Tuesday evening in January at Oakwell.

It's the manager's job to keep the players focused but in the build-up to a match like this, you also really need your senior pros to help you out and that's why the likes of Neil Harris and Gordon Greer will have a big role to play this week and on Saturday itself.

Greer's banned for the game after his moment of madness in the second leg of the semi-final but he can still have a big influence on the team and how the skipper conducts himself will rub off on the younger, more inexperienced Swindon players. It's the same for Harris in the Millwall camp. He's been round the block more than once in his career and needs to be exuding a calm confidence in and around the squad as the game gets closer.

Millwall don't have the best of records in the play-offs but I don't think that is going to be a big factor. It may make their fans more anxious at Wembley on Saturday but players really don't think in terms of records or statistics once the whistle goes and the match starts.

Swindon remind of my Oldham days when we had a 'if you score two, we'll score three' mentality and they're certainly dangerous going forward. They're a bit leaky at the back and Greer will be a big loss but I'd be surprised if they don't score at the weekend.

The winner, of course, is anyone's guess. The one thing guaranteed is for one set of players it could be the greatest day of their careers and for the others probably the worst.