Star Perth Glory midfielder Diego Castro will miss between two to four weeks of A-League action, starting with a crunch match against Sydney FC.
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 copped a knock to his knee during last Friday's 2-0 loss to Macarthur FC, and will miss between two to four weeks.
"At the moment it just seems like the capsule inside his knee has produced swelling," Glory coach Richard Garcia said.
"But there's no real signs of anything major to be concerned about. It's about trying to get that swelling down. It's nothing too bad at the moment."
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.
The Spaniard missed three games at the start of the season, with Perth losing two of those.
His return to the side sparked a three-match winning run.
Garcia is confident his team will be able to perform strongly even without Castro.
"We're not about one person, we're about the whole squad," Garcia said.
"It's about everyone stepping up. That sometimes gets lost in translation, where people think it's about one or two.
"He's an important part of the team, but so is everyone.
"The guys that come in and play need to come in and add their talent to the game."
Defender Jonathan Aspropotamitis returns from suspension, while striker Andy Keogh could return from injury.
Perth are still without Socceroos winger Chris Ikonomidis (knee) and striker Nicholas D'Agostino (hamstring).