Tim Cahill is in doubt for Australia's match against Costa Rica on November 19.
The Socceroos star's MLS season was cut short on Wednesday when his New York Red Bulls were surprise losers against Houston Dynamo in the Eastern Conference semi-finals.
The attacking midfielder could hardly run towards the end of the 2-1 extra-time home defeat and admits he is unsure if he will be able to join up with Australia's squad ahead of the friendly at ANZ Stadium in Sydney.
Hoping the injury was caused by cramp and not a muscle strain, the 33-year-old will monitor the injury over the weekend.
With the Red Bulls out of contention for the end of season MLS Cup, Cahill has no domestic football commitments for the next six weeks, which will allow him to focus on regaining full fitness.
But it might also hurt his match fitness as the Socceroos begin a new era under Ange Postecoglou.
There is strong speculation Cahill is in line to replace the under-fire Lucas Neill as Australia's captain.comments