ADELAIDE star Eddie Betts faces a last-minute fitness test before he's cleared to play in Sunday's Showdown against Port Adelaide at Adelaide Oval.

The electric small forward has been named in the Crows' extended 25-man squad to take on the Power after having his appendix removed early last week.

It appears he will be included in the final 22 to be confirmed on Friday afternoon, before being put through his paces at a closed training session on Saturday morning.

"I've got a test tomorrow," Betts told radio station Five AA.

"We train tomorrow, I'll go through a little test and we'll see from there."

Adelaide's thrilling draw with Collingwood last week was the first game Betts has missed since joining the Crows in 2014.

The Crows were down by 51 points early in the third quarter before staging a miraculous fightback, finishing with Mitch McGovern kicking a goal after the siren to secure two premiership points.

"It was probably the most exciting and frustrating game I've ever watched," Betts said.

"Because you know game style so well, you can see stuff happening either way.

"The second half just showed the way we can play, and to get ourselves out of it was fantastic."

Betts dismissed any thought the Crows would keep something in reserve in case they had to face the Power in the finals.

"It's pedal to the floor, we do that every week, we don't go out and hold anything back," Betts said.

"Showdowns are always massive games, no matter where you are on the ladder.

"This one is one of the biggest Showdowns I've ever been involved with, apart from the Phil Walsh one (in 2015)."

Power vice-captain Ollie Wines said his club was embracing the underdog tag after losing the past four Showdowns.

"This is a game, tipping-wise, people probably don't have us winning, but we see it as a great opportunity to get one up," Wines said.

"If it does lead to another Showdown in the final, I can't imagine how big that would be, but we'll let that take care of itself down the track."