West Ham shot-stopper Arnold, 26, is applying significant pressure on the long-time incumbent after an impressive start to life in the FA Women’s Super League.
Williams, for her part, has overcome an ankle injury and after a frustrating wait has started the last four games for Arsenal, picking up two clean sheets for Joe Montemurro’s high-fliers.
Whilst four-time FIFA Women’s World Cup participant Williams, 32, is back in business, it’s clearly game-on between the long-time friends and rivals heading into next year’s rescheduled Tokyo Olympics and the 2023 home World Cup beyond that.
Arnold - six years Williams’ junior - has started nine games for the Irons and has 24 Matildas caps to Williams’ 88.
Asked if she felt she was getting closer to possibly supplanting the keeper who showed her the ropes when she broke into the Matildas fold at just 17, Arnold replied: “That’s a question you’d probably have to ask the new coach, to be honest.
“I haven’t had any contact with him at this stage but of course I’m happy to be playing regularly at club level.
“Most of my experience has been in the W-League (at the likes of Canberra United, Perth Glory and Brisbane Roar) and to get a starting spot at West Ham has really helped my game.
“Hopefully I can translate that to the Matildas whenever we get together next (amidst a coronavirus-ravaged schedule).
“I came into the Matildas setup very young and Lydia took me under her wing and I’ve learned a lot from her.
“Over the years the competition has sort of developed and it’s a very healthy competition.
“We’re good friends and there’s no bad blood there whatsoever.
“Of course everybody wants to play and have that ambition to get in the starting team.
“That’s understood throughout the whole team - it’s not just goalkeepers. We respect each other but (competition) is how it has to be.”
Arnold has kept three clean sheets to date in a team wrestling for points at the wrong end of the table.
With Gustavsson hoping to head up a Europe-based camp during the February window, Arnold might be able to show him first-hand how far she’s come.
“I think shot-stopping-wise I’ve improved,” she explained. “I’m quite different I think to Lydia.
“She’s an instinctive shot-stopper whereas I prefer the ball at my feet a bit and I like to be a part of the build-up.
“We both bring different aspects to the team but of course you have to be good at all of it.”
No games are pencilled in yet but Football Australia is aiming at the very least to give the green light for a training get-together, with 21 Matildas scattered across Europe.
“I’m at a good club doing what I can do,” said Arnold. “It will come down to what the Matildas coach wants (going forward).
“I think I’ve put myself in the best position I possibly can.”
With the Matildas “hanging out” for a long-awaited reunion, Arnold added: “It makes a lot of sense for us all to get together in Europe with so many of us here.
“But the way things are with the coronavirus everything is up in the air and nothing is confirmed.”
As London locks down amid a recent COVID-19 upsurge - an outbreak which has affected 10 of the West Ham staff and players - Arnold won’t be back in action again until after the winter break, with 10th-placed West Ham travelling to Manchester City on January 9.
“We’re all self-isolating for 10 days, so it’s going to be a lonely one on Christmas Day,” she explained.
Arnold counts fellow Matilda Emily van Egmond as a teammate in east London, adding: “We’re both really enjoying it here.
“I’ve been pleasantly surprised by the quality of the league.
“Every game and every training season is so competitive.
"It’s something I’m not used to but it’s something I’ve needed in my career.”
