Organisers are looking to add extra seats at Newcastle's Hunter Stadium for a potential Asian Cup semi-final blockbuster between Australia and defending champions Japan.

The venue is the smallest of five being used for the tournament and can accommodate only about 23,000 people in its stands.

Hunter Stadium, which hosted the Japan v Palestine match earlier in the tournament, is operating at the reduced capacity of 23,000 for the Asian Cup. Credit:Ryan Osland

That's about 10,000 short of full capacity because the Asian Football Confederation has prevented the sale of tickets to the two non-seated areas behind the goals.

But the home of A-League's Newcastle Jets may host the biggest match of the Cup so far.