Sterling scored two goals and made two more in Sunday's 6-1 win over Southampton - a result that returned City to the top of the Premier League.

He has scored six times in nine games in 2018-19, having scored 10 in his first season under Guardiola (2016-17).

Asked what had changed in the England forward, Guardiola replied: "His head."

The Spaniard added: "The first season, he was scared. He was looking, who is the guy I am going to pass the ball to?

"We spoke about that and said: 'Try to score goals. Now you have the feeling, where is the goal and go over there.'

"I have the feeling he is now enjoying scoring goals and making assists. He is becoming a winning player. He is stable and is focused on what he has to do to become a better player.

"He is more mature now than he was when we first met at the club. He believes more in himself. Hopefully he can be more ambitious and think he can improve. He is 23 and he can be a better player."

Guardiola was asked if Sterling can now be considered amongst the world's best players, but replied that the England international still has work to do to be ranked as such.

"He is a top player but still is so young to be considered the world's best," said the City boss.

"He is in incredible form, he is sharp, fast, clever, fighting, decisive, he can play both sides and can play in the middle and receive the ball between the lines and commit the centre-backs with a lot of aggressiveness.

"It was an incredible performance but still with the young guys like him and Leroy [Sane] I would feel he can improve.

"Still he loses simple balls, like the Tottenham game, when he made an amazing assist in the first few minutes but then lost a lot of balls."