"We've been building great things and the club's come such a long way in such a small space of time in the last six months," the 32-year-old said.
"But we are still building and we know we need to get results and there's no better way than to go to Sydney and pick up three points."
The last time Wellington played Sydney FC across the ditch, in January, they met an Alessandro Del Piero masterclass as the Italian forward scored four goals in a 7-1 rout.
Sigmund has clear memories of that day and will be keen to keep a lid on Sydney, who have won three and lost three this season, as he reunites with skipper Andrew Durante in the heart of defence tonight.
"It's like a marriage, me and him, at the moment," Sigmund said of Durante. "We always know what each other's doing, so I love playing with him. He's a top-quality player."
Phoenix goalkeeper Lewis Italiano has recovered from an ankle injury Leo Bertos and Kenny Cunningham come in to the squad from the side who drew 1-1 with Perth.