His mind was likely racing having just won a rookie contract with the Sydney Thunder.

Slater was the pick of the bunch as 15 young hopefuls put their hand up for a spot with the reigning Big Bash League champions.

Wagga Wagga's 15-year-old leg spinner Rachel Trenaman became the club's first female regional rookie search winner.

Slater trialled last year when his former teammate Mac Wright won the Thunder rookie contract that catapulted him into Tasmania's ranks.

"I guess [last year] prepared me for the experience," Slater said.

"I think that helps with anything if you've been through it already you can prepare a lot easier.

"Obviously there is a heap of experience up there and some great talent, and you have plenty of people to learn from. That's the main thing that I'm going to try and get out of this, is learn as much as I can."

Thunder general manager Nick Cummins said Weston Creek Molonglo "must be doing something right" with Slater showing a marked improvement over the past 12 months.

"I asked [Slater] if he'd grown, he doesn't know but he's definitely a bit stronger and a bit faster than last year so he's got some real potential," Cummins said.

"I think he's got a bit of Nathan Coulter-Nile about him with the way he bowls and his build. [He's] very powerful and he's still growing I think."

The Thunder brought rain for the second year running, so the hopefuls headed to Kaleen's indoor centre where the nets were divided into three facets of the game – bowling, power hitting and stroke playing.

Trenaman said "lots of questions will be asked" when she heads into camp in the lead-up to the Thunder's WBBL title defence.

"[I'm] just gobsmacked and honoured and privileged," Trenaman said.

"Just being around the whole environment and captain Alex Blackwell, I think it will be an awesome experience."

Cummins said the pair will arrive in camp at the same time as the rest of the squad as the club coaches prepare to take a "disparate group of people and make it a team".

"By dropping them right in the middle of that they get to see how you go about preparing for a tournament," he said.

"I think one of the biggest challenges for young cricketers coming through, it's not really the skill side it's actually understanding what it takes to perform at the elite level.

"For Joe bowling next to Clint McKay or for Rachel bowling with Stafanie Taylor or Maisy Gibson, she'll see what level and extent of preparation they go to. Then they usually take that back into their career and then they take the next step."

While Trenaman secured the coveted rookie contract, Ginninderra's Jess Howard has also been given an opportunity to train with the club.