GREATER Western Sydney will be without ruckman Rory Lobb for at least the next month with a back injury.

Lobb was taken to hospital during the Giants' win over Gold Coast in round 12 and was cleared of any significant damage, with the club fearful he had suffered a punctured lung.

But the big man was still in pain during the Giants' bye week, and more scans revealed a small fracture in his thoracic spine.

It's a huge blow for the West Australian who battled a groin issue in the pre-season, then suffered bone bruising in his knee against Sydney in round three, which caused him to miss another four matches.

Forward Daniel Lloyd is also expected to miss 4-6 weeks after straining his medial ligament against the Suns.

Coach Leon Cameron said Lobb's rehabilitation will start with plenty of rest, before he increases the intensity of his training.

"The crack is really small but it's in one of those really awkward spots in his back," he said.

"We've got to be really careful that it doesn't turn into a bigger issue later in the year.

"It's really disappointing because it was his fifth game back from his knee, and he was just starting to get some momentum, but unfortunately he's not going to be playing for four or five weeks.

"He wants to get some continuity with the midfielders too, and that’s what we want as a club, but that’s what happens."

Dawson Simpson and youngster Matt Flynn are in the frame to replace Lobb, but in better news, vice-captain Stephen Coniglio (concussion) has been cleared to face Brisbane on Saturday.

Star forward Toby Greene (foot) continues to make slow progress in his bid to return for his first match since round five but completed a running session in driving rain on Tuesday.

The 2016 club champion and All Australian has played just three games this season after he missed most of the summer with a broken toe, then hurt his hamstring in the Giants' season opener against the Western Bulldogs.

Greene made it back for the Giants' round four win over Fremantle but pulled up sore following the club's draw with St Kilda and hasn't been seen since, but Cameron said he hopes to have his gun back in the next month.

"Toby has probably turned a corner," he said.

"But we can't just expect to say 'he's right, let's play him' because he's missed seven games now.

"He needs to have three weeks of good training and get some running and footy load into his body, so we don't have a hamstring issue like we had in round one."

Cameron said midfielders Brett Deledio (calf) and Tom Scully (ankle) are unlikely to feature in the short-term future, with both players 4-6 weeks away from returning.