Finnis, who started at the Saints in May after leaving the CEO's role at the AFLPA, said Pelchen's departure had nothing to do with any failing on the former head of fooball's behalf.
Instead, it was about tightening things up at the Saints and ensuring the club ran efficiently.
"I don't think it's a deficit thing [with Pelchen]," Finnis told SEN on Tuesday afternoon.
"We've recontracted 19 of our young players now for the next few years, and we want to make sure the environment in which they work in is absolutely uncompromised in the pursuit of excellence in a high-performance sense.
"[This is] in the way you combine coaching with conditioning with welfare and medical – these all require a high level of expertise in really moulding those different parts of the business together and that's what we see going forward.
"We're really strong, and have been really strong, in strategy and list and recruitment, but we felt that there was a harder edge and a bit more work we could do in terms of our football program itself and that's the change we decided to make."
AFL.com.au understands Pelchen wants to stay in football after successful stints at both Hawthorn and Port Adelaide before he joined the Saints.
Carlton is known to be seeking a list manager, while there has been speculation that Greater Western Sydney list manager Stephen Silvagni will finish up after the NAB AFL Draft on November 27, potentially creating a role at the Giants.
Pelchen was one of the main instigators of the Saints' push into New Zealand, a project that has secured them a home game in Wellington on Anzac Day each year until at least 2018.
Finnis said his departure wouldn't reduce their involvement with the country, with the Saints already keen to add to international scholarship holders Joe Baker-Thomas and Giovanni Mountain-Silbery.
"We had a meeting yesterday where we were talking about a couple of international scholarship players for next year," he said.
"We've got a 16-year-old young man from Auckland who's doing some training with us and we've got Joe Baker-Thomas so I think you'll see more players from New Zealand joining our list over the next couple of years."
Finnis hasn't always seen eye to eye with the AFL, having headed up the players' association for over four years.
But he said it made sense to work together in righting the Saints' financial woes to get the club back to where it needed to be.
"It's a reality that we live with and my job is to put in place the building blocks that are going to turn that around and alleviate that," he said.
"The AFL has got our back on that, they understand where we're at and our job is to be really prudent in the expenses side of things on football and also guide the revenue.
"That's where the upside is for our club and we're hopeful we'll be able to make some positive announcements over the next period between now and Christmas to support that."
Finnis has made multiple changes to roles within the club since his arrival in May.
The jobs of chief operating officer Terry Dillon and general manager of commercial operations Shane Wakelin were cut and their responsibilities consolidated into one role, which went to Christine Finnegan from the Melbourne Rebels and AFLPA.
Then, list manager Ameet Bains was promoted from list manager to chief operating officer in July.
Finnis strongly denied the parting of ways with Pelchen had anything to do with a recent report in the Herald Sun that detailed an extensive document that outlined how the Saints would construct a premiership winning team by 2020.
Pelchen was the spokesperson for that report.
"I have to say, I was quite happy with that coverage," Finnis said.
"We're a club that I think has got to sell our story.
"I'm not sure where that [rumour] came from and there's certainly no basis to it."
Gemma Bastiani delves into stars of the 2024 Telstra AFLW Draft
10:57
The most spectacular marks of 2024
Relive the best marks of the 2024 Toyota AFL Premiership season
01:21
Why McDonald could become AFLW's best key forward
Gemma Bastiani delves into stars of the 2024 Telstra AFLW Draft
00:15
Opening Round QLD | March 6-9
Be part of AFL Opening Round to kick-off the 2025 Toyota AFL Premiership Season in QLD. March 6-9. Brisbane Lions host Geelong at the GABBA and Gold Coast SUNS take on Essendon at People First Stadium.