O'Sullivan has joined Canberra United as a guest player, which limits her to seven non-consecutive games, and is confident the squad's international flavour will ensure they gel quickly.

The 24-year-old has already played 60 times for Ireland and helped the North Carolina Courage win the National Women's Soccer League title in the United States last season.

She also won the Courage's most valuable player prize, and now she hopes to help Canberra United win their first W-League championship in four years.

"The opportunity came out of the blue a bit ... I thought it was a good option to experience something else in a different league and I'm excited," O'Sullivan said.

"I know the games are going to be tough, but all the girls are working hard so we're looking forward to it. It's been a great year so far, it was amazing to win the championship and I definitely didn't think it would happen.

"[Coach Heather Garriock] and I haven't spoken about which games I'll play, it will be a hard decision so we'll just wait and see."

The new-look Canberra squad will feature players from Ireland, Scotland and South Africa to blend with rising talent from Australia.

Scotland's Rachel Corsie will captain the side, while O'Sullivan will add valuable experience and leadership to a relatively young roster.

But O'Sullivan admitted she didn't even know there was an Australian competition in the early stages of her career, which started at Cork before moving to the US in 2016.

"We've got a good team, a mixture of youth and experience so there's a good buzz around the change room," O'Sullivan said.

"Before I came to America, I didn't know [the W-League existed]. I probably never thought there was a league in Australia. But I've talked to players coming here in the [US off-season] and I can get a taste of it now."

Garriock added: "It is great to have Denise in town ahead of the season and she is already making an impact in training.

"She has already proven herself both in the NWSL and at international level so for her to be in
Canberra as our guest player this season is great for our team.

"For a 24-year old her list of accolades is brilliant, and to be voted the MVP of a title winning team in the NWSL tells you all you need to know.

"To have a player of Denise’s calibre at Canberra United is so important. Her work ethic, winning mentality and leadership qualities will be crucial for us, she has exception skill and vision and I am sure that she will be a fan favourite."

O'Sullivan, who has been playing for Ireland since she was 17, arrived in Canberra this week to start preparations for the season, with United to start their season against Melbourne City at McKellar on October 28.

"This season has been amazing with the Courage, and I’m hoping to bring my form and continue it here, and to test myself in another major league," O'Sullivan said.

"I’ve played with and against some of the best players in the world and have learnt a lot from top coaches, and I’m excited to bring those experiences to Canberra and make an impact while also learning more from new people in the W-League."

CANBERRA UNITED'S DRAW (home games in bold)

October 28: Canberra United v Melbourne City at McKellar, 4pm

November 4: Canberra United v Perth Glory at McKellar, 4pm

November 17: Newcastle Jets v Canberra United at Newcastle, 7.30pm

November 22: Adelaide United v Canberra United at Coopers Stadium, 7.30pm

December 2: Canberra United v Sydney FC at McKellar, 4pm

December 7: Western Sydney Wanderers v Canberra United at Spotless Stadium, 5.20pm

December 22: Melbourne City v Canberra United at AAMI Park, 5pm

December 27: Canberra United v Brisbane Roar at McKellar, 7.30pm

January 3: Perth Glory v Canberra United at Dorrien Gardens, 8.30pm

January 13: Canberra United v Adelaide United at McKellar Park, 4pm

January 17: Canberra United v Melbourne Victory at Seiffert Oval, 7.30pm

January 25: Brisbane Roar v Canberra United at Suncorp Stadium, 5.20pm