An opposed training session with the Sydney Roosters' Jersey Flegg side has women's skipper Simaima Taufa believing they've got the firepower to challenge for the inaugural title.

The women's Roosters side was unable to have a trial game as part of their preparation leading into Saturday's first ever NRL Holden Women's Premiership clash, instead relying on the partnership with their male counterparts.

Aged between 18 and 19, the Jersey Flegg side was understood to be hesitant at first engaging in contact, but both line-ups ended up getting value out of the training session.

The Roosters' Flegg side will play Newcastle in a semi-final clash at Jubilee Oval on Saturday.

"We gave each other a good run for our money," Taufa told NRL.com.

"We did it at Allianz Stadium in front of a crowd so we're just happy to have been able to do that. It wasn't full-on, but just to see how your structure will run, how the game plan can work smoothly and how crisp the passes are getting.

"When you run it at training against each other, it's repetitive. But when you run it as a full squad against a side you know nothing about – men or women – it opens your eyes to the possibility of putting out a quality game."

Roosters women's coach Adam Hartigan believed both sides benefited from the training experience.

Roosters captain Simaima Taufa. ©NRL Photos

"The Jersey Flegg boys did a really good job, a bit unconventional for them at the start," Hartigan said.

"It was different but we needed to have an opposition against us so we can run some sets and plays."

The Tricolours have lost Ruan Sims to a hamstring injury after the experienced leader was named in the reserves list earlier in the week.

Sims has endured a tough season on the injury front with the latest setback based on precaution with the competition only a month long.

"It's early to say with Ruan," Hartigan said of her immediate future.

"It would've been too much of a risk. It looks to be a grade one (strain), if Ruan played she might have torn it, so we decided to rest her."

The Roosters side have been tipped by many to take out the competition with a star-studded line-up at their disposal.

But newly-appointed captain Taufa wasn't buying the favouritism tag, particularly against an unheralded Warriors outfit on Saturday.

"We're not going to underestimate them," Taufa said.

"They are a squad with a lot of Kiwi Ferns, a lot of experience with Laura Mariu as captain. They've got it throughout their line-up and then we also don't know about some of their other players.

"They can possibly be amazing talents coming through their system so we would be silly if we didn't think otherwise."