Ever since Franklin’s high-profile move to Sydney from Hawthorn, the eyes of the AFL world have been on the superstar forward.
Jack, one of the Swans' most driven and disciplined players, says he had been caught off-guard by Franklin's performances in training so far.
Asked if anything had surprised him since Buddy's arrival, Jack replied: "Probably how focused he is.
"I think that's something that I've really been taken aback by.
"He's certainly made a positive impression on the club, he's training hard and he wants to win premierships, which is what we're all about and that's why we're rapt to have him."
Jack's comments came after Jarrad McVeigh said last week that Franklin had given his new club some great insights into how the flag-winning Hawks operated.
The Swans know that questions about Franklin will be a regular occurrence throughout 2014.
"Lance is fine. He's fitting in really well," Jack said.
"Every press conference we do, everyone's asking about him.
"His knowledge of the game and experience he brings is something we're really valuing."
Franklin and the Swans had some unusual training partners at Lakeside Oval on Wednesday, with English rugby league outfit Warrington Wolves joining the session.
The teams took part in some tackling drills and an AFL skills session, with some of the English players struggling in the Australian heat.
One man used to the conditions was Warrington's new signing Roy Asotasi, a former New Zealand Test captain who made his name in the NRL with the Bulldogs and South Sydney.
Asotasi labelled the Swans a benchmark professional sporting team, particularly when it comes to leadership.
"Credit to these (Swans) boys, they're not too bad when it comes to the defensive side," Asotasi said.
"We did some tackling skills and they had a dig.
"They're a benchmark in terms of their leadership and how well they work together and make each other accountable.
"That's important in a team environment, it's not about one person and you need to all be on the same page."
Jack, the son of former Australian Test representative Garry Jack, enjoyed seeing some of his teammates take on the league players, including the 181cm, 106kg Asotasi.
"I stopped playing league at 15, so I certainly enjoyed it, but seeing the boys out there tackling and running into pads, I'm pretty glad I chose AFL," he said.
"I saw Ben McGlynn line up on (Asotasi) and I thought that was a stupid move by him. He's four-foot-nothing.
"But a few of our boys are competitive beasts and wanted to have a go and it was quite funny to watch."
Roy Asotasi tackles Ben McGlynn at training on Wednesday morning
