Tom Rogic has been urged by his national team coach to leave Celtic by on loan so that he can begin to establish himself as Australia's most influential player in next summer's World Cup.

The 20-year-old made a classy cameo in Tuesday's 1-0 win over Costa Rica but Ange Postecoglou claims the midfielder was not fit enough to play a full match due to his lack of game time in Scotland, having already warned that his place at the finals in Brazil may be in jeopardy if he does not break into Neil Lennon's side.

The idea of linking up with Graham Arnold, his former Central Coast Mariners manager who is now in charge of Japanese outfit Vegalta Sendai, has been mooted in Australia and Postecoglou would support such a move. "I think that would be fantastic," he said. "There isn't a player on the planet who wouldn't think for the next six months, ahead of the World Cup, that the best move would be to play regular football.

"Arnie [Graham Arnold] knows him and we know Arnie is a fantastic coach. He's got the best out of Tom Rogic in the past and the Japanese league is a strong competition. I don't see why not.

"The reason I didn't start him [against Costa Rica] is simply that he is not capable of playing 90 minutes right now. It was great to get a half-hour cameo, but if Tommy is playing regular football he becomes a leading light in our national team not just now, but for the next 10 years."