Moeen Ali insists batting aggressively "is probably the only way I can play in one-day cricket" ahead of England's opening Tri-Series match with Australia in Sydney on Friday.

The Worcestershire all-rounder has hit rapid half centuries in warm-up matches against the Australian Capital Territory X1 and Prime Minister's X1.

It follows on from the similar style Moeen used in the ODI series in Sri Lanka when he finished as England's second highest run-scorer in the seven matches behind Joe Root.

He said: "If we are going to win the World Cup and be a successful one-day side we will need good starts. "We need guys in the top three who can set the standards for everyone else and be expansive and take some risks.

"Aggressively is probably the only way I can play in one-day cricket. Sometimes I face 30 balls and I feel as though I’ve faced 50 or 60.

"It’s the natural sort of thing I’ve done for a few years now. I feel it’s the best way for me to play and if I’ve got any doubt I just tell myself to go hard and not go into a little shell.

"In Sri Lanka I got bowled first ball having a slog. It’s not nice to get out first ball but I’d prefer to get out having a go rather than just blocking it."

Moeen has a new partner at the top of the batting order in his former Warwickshire team-mate Ian Bell who hit 187 against the PM X1.

It is his fourth different opening partner in 50 over cricket for England after Michael Lumb, Alastair Cook, Alex Hales and now Bell.

He said: "I wouldn’t say it’s difficult to change partners. I just go and play how I need to play on that particular day.

"The good thing about it is that we now have a left and right hand combination and that can make it a little more difficult for the bowlers.

"I’ve batted with Belly quite a bit. When I first started at Warwickshire he was there and I enjoy batting with him.

"He’s quite busy, he’s very good at getting singles as well as the boundary shots and is a classy player so I really enjoy batting with him and hopefully we will be a good combination together.

"I think out styles compliment each other. We’ve both got to bat our way.

"If he gets a hundred ball hundred, that for him is the way to go. He should just bat the way he does and not worry about being too aggressive and hopefully I can take a bit of pressure off him at the other end and make it easier for him."

Moeen is also preparing as if he will have a key role to play with the ball with England this winter.

He said: "Sometimes it’s difficult to bowl on pitches that spin a lot because your line changes.

"Against top quality players, I feel you have to try to hit the stumps as quickly as you can so it’s sometimes easier when there’s not a lot of spin.

"That’s how I feel anyway. But it will be tough because Australians play spin very well and are very aggressive against spin.

"I’m going to prepare like I’ve got a big role to play with the ball.

"There will be times when perhaps I won’t bowl as much as Treddy (James Tredwell) and vice-versa but I will definitely prepare like I’ve got a big role to play."

Moeen reiterated his belief that he will continue to improve at international level.

He said: "I definitely feel I can get better. It’s been one year of international cricket and I feel like I’ve got better already so hopefully I can improve.

"I do feel like I’ve got a lot more to show."