GREATER Western Sydney will be without ruckman Braydon Preuss for half of the season with the recruit to undergo surgery on his shoulder. 

The 208cm giant hurt his shoulder at training on Monday and subsequent scans revealed he will require a full reconstruction. 

The 25-year-old will go under the knife on Thursday and is expected to be sidelined for up to five months. 

WHO IS MR POPULAR? Preuss is currently in 40 per cent of Fantasy teams

"This is obviously hugely disappointing for Braydon who has come into our club and had an immediate impact on the training track," Giants footy boss Jason McCartney said.

"He's had a huge pre-season and was tracking really well before his injury on Monday.

"Braydon will now attack his rehab with a view to returning to the field during the middle of the season."

Preuss, who was traded to the club in exchange for pick No.31 last November after 18 senior games with both North Melbourne and Melbourne, had been tipped to become the club's first-choice ruck option this season.

With youngster Kieren Briggs (hip) also enduring an interrupted pre-season, the bulk of the responsibility is again expected to fall on the shoulders of 34-year-old Shane Mumford. However, the club also has high hopes for uncapped Academy graduate Matthew Flynn.

SCRATCH MATCHES Who your club is playing

The Giants also remain in the dark as to whether Lachie Whitfield will recover from a bruised liver in time for round one, with the gun midfielder's unusual injury making it difficult for the club to put a timeframe on his return.

Whitfield is expected to resume running and weights work in the next week, but is not expected to resume contact work for at least the next month after suffering the injury during a collision at training.

AAMI COMMUNITY SERIES Check out the pre-season fixture

The club has already ruled Whitfield out of a pre-season practice match against Sydney in the coming days, as well as its AAMI Community Series clash against Brisbane on March 4, but is not certain whether he will face St Kilda in round one in 32 days' time.

"It was really unusual," Cameron said.

"Lachie is so brave, playing a bit of match play and he just backed into a pack. He was a bit sore around the ribs and we scanned him the next day and we found that he had a bruised liver, which is the first time I've ever heard of it.

"You ask how is his health and how is he going to be and what could be the time out of the game? The big thing with Lachie is that he's taken about six or seven days to initially get over the hit. He's probably not going to play for the next four or five weeks.

GET THE FANTASY APP Download from the Apple Store or Google Play now

"I can't say whether he's going to be ready for round one yet, because the doctors and the specialists need to see him week-by-week just to see how that bruise on his liver is actually mending.

"He's in a really good spot the last three or four days. He could take some really good steps forward over the next couple of weeks, but he could also take a couple of steps back. It's a little unknown.

"He will not be playing in any of the pre-season games, but Lachie's fitness base does allow him to step back into our program pretty quickly."