IT WILL be May Day tomorrow, but for the Swans it is also D-day – the day everyone gets a better idea of just how serious a threat they will be this season.Sydney have stunned many by topping the ladder after five rounds, winning four games by healthy margins. But no one – critics, fans, nor even the players or coaching staff – is getting too carried away, realising their four victims are all likely to be inactive during September.That changes tomorrow, when the Swans host Brisbane, considered to be legitimate top-four contenders. Then come Geelong, the Bulldogs and Fremantle, and by the month’s end we will know how the Swans stand.”Our ladder position … as a player, I don’t really even look at it,” claimed co-captain Brett Kirk. ”It’s more about how as a team we are going, whether we are playing the right game plan and playing for four quarters.”Probably over the last few weeks, in patches, we’ve played some good footy, but we’ve been up and down, and to beat Brisbane it needs to be a big four-quarter effort.”Kirk agreed the next four weeks would be the acid test.”We play our next four teams who are all in the top five or six positions, and they are all playing really good footy at the moment, but we’re not really looking too far into the future, just this week against Brisbane, we’ll get a bit more of an idea from there.”You can only play as well as the opposition you’re playing against. I guess from outside the walls we’re not too worried how people are seeing us. Nobody really gave us too much of a hope early on, and people will obviously judge us come Saturday night.”Coach Paul Roos admitted he was a ”little bit” surprised but pleased to be 4-1. ”The kids look at it and everyone else gets excited about it, but when you’ve been in footy for so long, it’s [the ladder] more of a reference point than anything,” Roos said.”It means nothing other than you’ve won four games. If we were 4-1 and fifth, it makes no difference to being 4-1 and first at this time of year.”I think we are playing really well, our personnel is really good, our game style has been standing up at this stage of the season, the players we’ve got from other clubs have performed extremely well. I think we’re in really good form and I think we’ll get a better idea [of where they are] after Saturday night.”I’d rather be up there than down the bottom, but it’s 22 weeks, it’s a long year, and I guarantee something: four wins won’t get up into the eight.”Roos, meanwhile, made just one change to the team which beat West Coast, replacing the injured Craig Bolton with Ted Richards.There had been some speculation that Roos might not go with Richards, and instead give Bolton’s defensive role to Nick Smith, leaving him then able to bring a midfielder into the team, someone like the speedy rookie Gary Rohan (who was named as an emergency). The one downside with that move, though, would be if Lewis Roberts-Thomson or Heath Grundy were injured during the game, and Sydney would be short one tall defender.”It was pretty much a straight swap for a defender,” Roos said.Brisbane have lost defender Daniel Merrett, out with a hamstring injury but have some handy inclusions in Justin Sherman, Luke Power, and Amon Buchanan.