'Annoyed' Thunder aiming to knock off Heat in Perth

The Brisbane Heat and Sydney Thunder will lock horns at the WACA Ground with the winner to face the Perth Scorchers in a WBBL preliminary final.

Sydney Thunder captain Heather Knight says her team are a bit annoyed at missing out on a home final, but she's backing the group to get the job done in foreign territory.

The WBBL finals start on Tuesday evening when the fourth-placed Thunder take on the third-placed Brisbane Heat at the WACA Ground.

The winner of that match will face the Perth Scorchers at the WACA in a preliminary final on Wednesday, with that victor to face top-of-the-table Adelaide Strikers at Adelaide Oval in Saturday night's grand final.

The Thunder were one of the form teams in the competition before losing five of their last six games to finish fourth.

A win over the Sydney Sixers on Sunday would have secured second spot for the Thunder and a home preliminary final.

But the nine-wicket loss means they must now win three matches on the road in order to snare the title.

"It's obviously annoying, but we have to park the fact that we lost the chance to stay in Sydney," Knight said.

"We're going to have to do it the hard way. I think there's a lot of fight in this group.

"We've played on slightly slower wickets towards the back-end, and we've probably found that a little bit harder as a batting group. We've probably lost our intent at times.

"But there's a lot of talent in that group, and we've just got to try to turn it around.

"We'll probably get a slightly quicker pitch at the WACA than the ones we've had towards the back-end of this group stage."

If the Thunder buck the odds to reach the title decider, Knight won't be available due to England's tour of India.

Scorchers duo Amy Jones and Nat Sciver-Brunt are among the English players in the same boat.

Jones wasn't likely to play again for the Scorchers this season anyway due to a calf injury.

The Heat's bid to snare a sixth consecutive finals berth was looking shaky following a three-match losing run.

But a 22-run win over the Thunder on Friday in Brisbane's final game of the regular season was enough for them to lock in a finals spot.

The Strikers ended their regular season with five straight victories to finish three wins clear on top of the table.