The club confirmed today that the knock he took in the weekend's game against Adelaide United will see him miss at least the next four rounds.

The pint-sized samba star suffered the injury early on in a crunching challenge with towering Ange Costanzo.

The 34 year old appeared to play on despite the hit but was obviously struggling with the pain, frequently trying to rotate it back into place before set pieces.

Today the club confirmed the medical team had told him to rest it for a minimum of four weeks. "He is going to be out for a month," admitted a club spokesman.

He is understood to have torn ligaments off his shoulder bone in the challenge.

The injury could require surgery to correct - which could put him out for most of the season - but Juninho has reportedly agreed to play through the pain barrier rather than go under the knife.

The marquee star's loss will be a huge blow for Sydney and their title dreams. Even after being out for four weeks, it could take another two months to get back to full match fitness again.

Juninho showed he was close to recapturing his full fitness and form in the Adelaide match, with sensational free-kicks and breathtaking passes, one of which created Brosque's goal.

Manager Branko Culina admitted "It's not good at all, devastating even.

"Hopefully it's a matter of weeks rather than anything above that, but the reports are he has torn ligaments in his shoulder, and how long that will take is in the lap of the gods."

He told the Sydney Morning Herald: "It's bad news for us, but that's the risk you take when you bring in a marquee player in a short season.

"If he's forced out of the game for the next four or five weeks, it's a bitter pill to swallow for the team, and the club."

The side was already struggling with injuries and international call-ups for the Olyroos and Socceroos ahead of this weekend's match against Perth Glory on Sunday.

Ruben Zadkovich, Mark Milligan, Alex Brosque and Clint Bolton will all be missing from Sunday's game because of Olyroo and Socceroo duties.

But skipper Tony Popavic is set to start after shrugging off a back injury he picked up in a collision with Bolton during the Adelaide match. Sydney's other Brazilian, Patrick, is also set to start, taking Brosque's place in the line-up.