MELBOURNE Victory will be anxiously awaiting medical tests to see how long Harry Kewell will be out after the Socceroo forward was forced to leave the national team squad ahead of tomorrow night's World Cup qualifier against Thailand.

Officials were expecting the 33-year-old to miss next weekend's clash with Perth Glory after he pulled out of the game in Bangkok with what was described as a muscle tear. But if the injury is hamstring-related Kewell could be out for longer.

Victory are anxiously awaiting test results for the injured Harry Kewell. Credit:Getty Images

He played 54 minutes in Australia's 1-0 loss to Oman in Muscat on Saturday morning. His form for Victory has been indifferent in the five matches he has played. Kewell made a bright start on debut against Sydney, but has so far failed to prove the inspiration he and the club had hoped when they signed him despite showing glimpses of his undoubted talent.

Victory is proving itself to be the competition's draw specialist, its 0-0 result in Gosford on Saturday night being its fourth draw in six matches.