Autralia's all-time leading goalscorer Tim Cahill is in doubt for the World Cup qualifying play-off against Honduras due to an ankle injury.

The former Everton attacker twisted his right ankle challenging for the ball and was substituted during the first half of his Melbourne City's 1-0 A-League loss to Sydney FC.

Cahill, 37, who scored a double to help the Socceroos get past Syria in their Asian play-off last month, went to hospital for scans on his ankle.

He may be in the twilight of his career but Cahill, with 50 goals in 103 internationals, has been Australia's go-to man in this year's World Cup qualifying.

Cahill will now have a race to be fit for the trip to Honduras, with the first leg on November 10 in San Pedro Sula and the return game in Sydney on November 15.