Defending champions Newscastle Wanderers won't return in 2020 to stake their claim at a three-peat, with their grand final opponents the Aidan Brice All Stars also not backing up next Saturday.

The Newcastle side's trip to the 10s tournament, which has traditionally been player run, hadn't come together with players unable to organise the trip to Orange, while the Aidan Brice All Stars were in the same boat.

Tournament organiser Fletcher Niven said "it's one of those sides where the players are getting a bit long in the tooth".

Meanwhile the Islander Boys and the Jack Blunt Legends have also dropped off the team list for 2020, with the latter having half its team list unavailable due to a wedding.

It's left the competition wide-open heading into this year's challenge, with two Orange City sides - both to be coached by Viv Paasi - to have a run, and Niven said there was a chance for the Lions to claim their first title in the near two-decade history of the 10s competition.

"A lot of those teams are made up of six or eight City players so we'll have them back this year and the firsts team will actually be a really good side, we could see them in the top four," Niven said.

"In 18 or 19 years we've never won it, we've had success in the Colts or the girls and maybe taken the overall plate but never won the seniors competition."

Those Lions sides will line up alongside Country Boys UNSW, Merrylands Wolves, Blacktown 1 and Canterbury to line up alongside a tribute side for former Orange City player Ricky Eggins and Duncan Young's "wildcard" side, which is largely made up of league players.

Young, who plays for both Orange City and Hawks, has dragged both players from Hawks and guys from Woodbridge Cup sides such as Cargo and Manildra for a run in a "wildcard" side.

"They'll be a bit of an unknown, they'll obviously be very good breaking lines but we'll see how they'll go in the ruck and maul," Niven said.

The Eggins Elite will be made up of former juniors and colts players who've moved to the coast for university, with plenty of former Lions to return to the den for the weekend.

Only three sides will line up in both the colts and women's competitions, with the Lions to come up against travelling UNSW and Blacktown sides in the women's fixture.

Meanwhile, Orange Emus' colts and Kings boys will line up alongside Orange City in the colts competition.

Niven said there was still spots for another women's or colts side who wanted to line up in the 10s tournament, with the club eager to fill a full bracket of four, and said if four sides threw their hats in the ring for the senior men they would open another pool there, too.

The Waratahs Sports Club 10s will be held on will be held on March 21 at Pride Park, with games from 1pm.