Greater Western Sydney posted their maiden win over the Swans on February 24, when the reigning premiers started their pre-season campaign less than five months after downing Hawthorn in the grand final.
The Giants cruised to a 24-point victory and looked a side that had made use of an extra month to prepare for the clash.
The Swans' form improved over the next month, but their only pre-season victory came against Gold Coast.
Compounding the shortened training time has been limited pre-seasons for Adam Goodes (knee), Shane Mumford (ankle), Mitch Morton (back), Marty Mattner (hip) and Nick Smith (knee) - all part of the Swans' 2012 premiership team.
In addition, they have lost defender Alex Johnson (knee) for the year, a key cog in their defence who played every game last year.
"There's no excuse now. Round one is here and everyone has to be ready to go," Jack said.
"... Early on in the pre-season some teams were really up and going and really flying. We were probably a little bit behind then.
"But we've trained really hard the last three or four weeks and we feel like we've made some progress.
"This week will be a test for us ... we're going to have to be on our game. We know that. They knocked us off in round one of the pre-season and we'll be looking to make amends for that."
Jack said he and Jarrad McVeigh had yet to decide who would address the side pre-match and toss the coin.
Having been promoted midway through the pre-season, it will be Jack's first AFL game as a skipper.
The 25-year-old didn't expect it would feel any different.
"I haven't really changed too much. I think the reason I got put in there in the first place was because I was doing some things pretty well," he said.
"So I'll continue to lead by example and hopefully it will show the way for the rest of the players."
