The task for O’Sullivan is clear – to help Liverpool move off the bottom of the Women’s Super League table and pick up points.
Gareth Taylor’s side remain without a win in the WSL this season but have acted in the transfer window, adding six new signings – including O’Sullivan.
The Reds, two-time WSL winners, moved into elite training facilities at Melwood in 2023 but have fallen behind England’s biggest clubs on the pitch.
“I think the club has a clear vision. They want the team, in the next few years, to be up there and winning WSL titles,” said O’Sullivan.
“I know the situation that the team is in and the main thing is to help them get out of that situation and out of the relegation battle. That’s what I want to give.
“When you come to a massive club like Liverpool, there’s an automatic responsibility on your shoulders to perform and to give 100% for the shirt.
“It’s really exciting for me and a big challenge. The club has a lot of history and has won numerous trophies. They’re one of the biggest clubs in the world.”
O’Sullivan, who has 128 caps for the Republic of Ireland, has watched Liverpool from afar and believes their performances deserved more points.
Now there is more competition in the squad from the new arrivals, O’Sullivan says Liverpool have been working on their “identity” in training.
“Their style of play is really going to suit me well. They’re a high-pressing team which I love as a player. I’m aggressive,” said O’Sullivan.
“They really do have a clear identity and style of play, and I know my role within the team now. You can hold each other accountable to that role.
“I think that’s a really, really positive thing and Gareth [Taylor] has been great so far. He’s a really good coach and the little details that he sees is something that I haven’t had that much of.”