Perth Glory's A-League finals hopes have been dealt a huge blow after star skipper Diego Castro was ruled out for up to four weeks with a knee injury.
Castro will miss between two to four weeks with the injury, robbing Perth of their most creative player.
Glory sit in ninth spot - five points adrift of sixth-placed Sydney FC.
The two teams will lock horns in Sydney on Wednesday night.
If Castro misses four weeks, he will miss crunch games against Sydney, Newcastle, Wellington, Brisbane, and Macarthur.
A best-case scenario of two weeks will still see Castro miss three games.
Castro's absence will leave a huge void in the midfield, with his experience and talent irreplaceable.
Glory are aiming to bounce back from last week's 2-0 loss to Macarthur.
Defender Jonathan Aspropotamitis returns from suspension.