PORT Adelaide skipper Dom Cassisi has declared himself a certain starter for Showdown XXXI at AAMI Stadium on Sunday, saying the impending birth of his first child won't affect his availability for the twilight clash.

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Cassisi's wife Maiya was due to give birth last week.

The premiership player, who has committed to being at the birth, was in doubt for the Power's last game against Melbourne a fortnight ago, only making the trip to Darwin on the morning of the game when his wife hadn't gone into labour.

Cassisi said he expected the birth to take place well prior to Sunday's game.

"I'll be there [at the game] with bells on," he said on Wednesday.

"She is due about now, so we'll be fine."

The resignation of Adelaide coach Neil Craig and subsequent appointment of caretaker coach Mark Bickley has added intrigue to the game between the last-placed Power and 14th-placed Crows this week.

The Power experienced a similar situation last season with Matt Primus stepping into the role as senior coach when his predecessor Mark Williams relinquished the position after round 15.

Cassisi described it was being a "difficult time" for the players, but expected the events of the past few days to galvanise the Crows.

"These things often can make the playing group a little bit stronger even though it is unfortunate for the individual coach," he said.

"The reality is you've just got to move on from it as soon as possible … you've got no other option.

"There are still points to play for and I guess it's just the ruthlessness of the industry.

"The weeks roll around. There's constant change and you've just got to keep focused on what's important for the club and the team."

Port Adelaide has won four of the last five games between the two teams, including a spirited come-from-behind victory in round four this season.

However, Craig's resignation has seen the Crows' odds of winning shorten.

Cassisi welcomed the expected response from Adelaide, but insisted his team also had plenty of motivation to win.

"I think both clubs have a lot to play for, they always do in the Balfours Showdown," Cassisi said.

"They are just big games. Last year, we won the Showdown after losing nine [straight] games. We can’t really control what's happened down the road.

"Both sides are desperate to win this game and it's going to be a great battle."

Forward Justin Westhoff is a chance to return after three weeks on the sidelines with a toe injury.

The lanky goalkicker trained on Tuesday and only needs to complete the club's main session on Friday to be recalled for the Showdown.

"I hope he (Westhoff) does play because he causes a few headaches for the Crows," Cassisi said.

"He won the Showdown Medal last time and has a pretty good record of playing well in the Balfours Showdowns."

Veteran Chad Cornes, who was called up to the team to replace Westhoff in round 16, is expected to retain his place despite the tall forward's likely return.

It would be the first time this season Cornes, Westhoff and full-forward Jay Schulz have played together in the same game.

Hamish Hartlett (shoulder) will also play against the Crows, but is tipped to book in for season-ending surgery after the clash with Collingwood next weekend.

Katrina Gill covers Port Adelaide news for afl.com.au. Follow her on Twitter: @AFL_KatrinaGill