Former Parkes Spaceman Neilson and ex-Forbes lock Mawhinney are players that St Pat's under 21s coach Tyson Medlyn hopes can help his squad make an impact in the new pre-season competition.

And given there are only five rounds before a top-four sudden death semi-final series, Medlyn hopes that impact comes quickly on Friday night when the Saints host Orange CYMS at Jack Arrow Oval.

"Cooper Neilson he's a halfback and he's played a lot of senior football, he's a very, very smart footballer and he's real calm. He trains really, really hard, he's got a real level head and the boys look up to him," Medlyn said.

"We've got another fella who's come over from Forbes, he's won a competition with Forbes a couple of years ago, young Aaron Mawhinney, he'll be another leader.

"I watched him at the nines competition over the weekend, to be an under 21s and the attitude he has - he tackles everything, he makes things personal, he's a competitor.

"So to have boys like that who are competitors to start with, that rises to the top ... they'll be there at the last minute."

With Group 10 rivals St Pat's and CYMS, a combined Woodbridge Cup outfit, Dubbo Macquarie, Forbes Magpies and Dubbo CYMS all fielding teams, the battle to win the inaugural under 21s crown will be hot.

But Medlyn said winning will definitely be the goal for his Saints - it's something all teams at the club will aspire to this season.

"At our club we've got Zac Merritt there who sets high standards and our goal at the club is to win everything whether it's a game of touch, or a game of cards - we want to be competitive in everything we do and that carries to our under 21s," Medlyn said.

"The 21s boys have been training with the seniors and the things Zac's been doing with them and a couple of other senior boys is giving that confidence and they want to win.

"All these boys are pretty competitive and we've got a lot of boys in our under 21s side who won an under 18s competition with Pat's, so they know what it's like to win and know the recipe for winning."

As Medlyn points out, many of those in his squad have enjoyed premierships in the past, but the coach has been drumming into them that results from previous seasons is no guarantee of continued success.

It will require commitment both in games and at training.

"I said to the young fellas that we might think we have a gun side, but so does everybody else. The 21s age group is probably where kids are at their prime, they're probably at their fittest and also at their fastest, so it's tough," he said.

"So I told our boys just because they won as under 18s doesn't mean they will do it again, we've got to work at all our training runs to try and be better."

While Medlyn expects three or four members of his squad will go on to play in premier league, he said the talent extends beyond that.

"There's a whole team of boys there that have the ability there to play first grade, it's just that there are a few senior boys at our club that will be hard to push out of first grade," he said.

"There are a few blokes there that may not have the most ability, but they've got the right attitude and over an 80-minute game, they're the type of blokes you want out there, they're the blokes you want to go to the trenches with if things do get tough."

The coach fully expects things will be tough against Orange CYMS, with their squad including those who have premier league experience such as halfback Josh Board.

"We've played some tough footy against CYMS, if they're not the benchmark they're not far off it," Medlyn said.

"They've had some really goods kids come through their junior system - they just seem to keep breeding good footballers and hard footballers.

"So we're really looking forward to it ... hopefully this competition will make them better footballers, it's good for football in the bush."

The Saints begin their Western under 21s campaign on Friday night, with kick-off in their clash with Orange CYMS set for 6.45pm at Jack Arrow Oval.

That will be followed by a Saturday double-header at Dubbo's Apex Oval with Dubbo Macquarie playing Woodbridge Cup at 4.45pm before Dubbo CYMS and Forbes Magpies do battle from 6.15pm.