WA Nationals leader backs fourth minister

West Australian Nationals leader Terry Redman says "of course" he would love to have a fourth cabinet minister from the party in the Liberal-led state government.

Asked about whether candidates could include Brendon Grylls, who has been a backbencher since resigning as Nationals leader in 2013, Mr Redman said he did not know who could fill the role and it was up to the premier.

"You make those calls as they come but if I get offered a fourth position, that would be a wonderful position to be in," Mr Redman told reporters on Monday.

Mr Redman will meet with Premier Colin Barnett soon to discuss a planned reshuffle ahead of next year's state election.