Kewell, who won 56 Australia caps, watched on as his fellow countryman Ryan, who has made 47 appearances for Australia, played all three group games in the World Cup this summer.
Ryan has established himself as first-choice for club and country and Crawley Town boss Kewell says he deserves to be No.1 for the Socceroos after impressing regularly in the Premier League last season.
He said: 'Maty should be the number one, 100 per cent. Unless we have another keeper who comes to a Premier League club and does the exact same or better than Maty Ryan, he should be the number one.
'He's playing at the highest level.'
Angry Alan Stubbs dubbed St Mirren's display against minnows Spartans 'unacceptable' after watching them scrape to a Betfred Cup bonus point on penalties.
Motherwell boss Stephen Robinson has called for more of the same from Elliott Frear after the player hit a hat-trick in their opening game of the season.
Motherwell kicked off their season in style with a 5-0 win over Edinburgh City in the Betfred Cup on Tuesday evening.
Steven Gerrard admitted he has concerns about Rangers' shot-shy strike-force after their stalemate with FK Shkupi in Macedonia.
Sunderland midfielder Wahbi Khazri has completed his move to French club St-Etienne, the Black Cats have announced.