The Forbes Magpies mentor is in his first year in charge of the green and white division's senior side, having taken over from Tim Ryan this winter.

The Rams broke through for their maiden under 23s victory last season, coincidentally against Sunday's opponent the Greater Southern Region Tigers, and Greenhalgh's hoping a mountain of muscle up-front will help Western get its 2020 campaign off on the right note.

Orange Hawks monster and former Parkes Spacemen Ethan McKellar will skipper the side from the backrow, with Group 10 player of the year Nathan Potts at lock and Lithgow prop Cody Godden also in the backrow.

Blayney's Joey Hobby is up front alongside new Bathurst St Pat's man mountain Taumutu Afemui-Nohotima.

Greenhalgh said the up-sizing of the Western pack ahead of Sunday's championship opener against the Tigers at Blayney stems from a suggestion from one of the two blues' best.

"Ethan mentioned to me at the start of the campaign he was looking to improve his skill level a bit and get out on and edge, and we've got a few big fellas in the middle which allows him to do that and gives us a bigger pack too," Greenhalgh said.

"Size can be an advantage against some of the sides we'll come up against. I'm happy to go with big."

If Western's powerhouse pack lives up to its potential, its all-Group 11 backline could have a field day.

Greenhalgh has called up a number of his Forbes players for rep duty while the rest of the bulk of the backline is from Wellington, last year's Group 11 champions.

Will Lousick and Mitch Burke, from the Cowboys and Magpies respectively, will be called upon to lead the Rams attack but it's a red-headed winger Greenhalgh is most excited about.

Canowindra's Regan Hughes has earned a shot on the wing for Western after impressing at the Rams trials and the experienced head coach says the Tigers' gun could have a field-day on the end of this backline.

"He could be a surprise packet in the coming years in this championship," Greenhalgh said.

"If we have a good run, you never know what might happen. He's a big, strong, fast, mobile fella and if I was a country selector he'd open my eyes."

Western thumped the GSR Tigers 60-12 at Bathurst last year and starting this year's campaign against the southern region outfit presents the Rams players with the ideal opportunity to kick off 2020 with a win.

Greenhalgh said his side's preparation hasn't been ideal, but a slick run at Parkes last weekend gives him hope Western can make a mark this campaign.

"I think they'll be tough, they always are, championship games," he said.

"There's lots of skill, it's a mobile side. I think they feel they've got a side that go a little bit further too."

The under 23s line-up for Sunday's clash with GSR Tigers at Blayney:

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