Coach Matthew Primus made good of his promise to promote youth this season in round one, leaving Cornes and forward Daniel Motlop, who was barred from selection for disciplinary reasons, out of the team to play Collingwood.
The Power recast Cornes as a forward over the pre-season, but couldn't find room for him in a team that included tall targets Schulz, Justin Westhoff and Daniel Stewart.
The dual All-Australian responded to his non-selection by kicking three goals for Glenelg in a SANFL trial game.
Schulz will be sidelined for up to six weeks and Cassisi said Cornes was a chance to play in the absence of last year's leading goalkicker.
"In Chad's case he's done everything right," he said.
"He's gone back to the Bays and played really well. Jay's injury is disappointing, but it might open the door up for Chad."
Primus' other option at selection is utility Nick Salter, who kicked four goals in the SANFL last weekend.
Most recently, Salter has been used in defence but the emergence of Jasper Pittard and Cam O'Shea could see him switched back into attack.
Defender Jacob Surjan, who is on the comeback from a knee injury, is a chance to play against West Coast, but classy midfielder Hamish Hartlett is unlikely to be available for selection after being concussed playing for West Adelaide.
Forward Brett Ebert copped a knock to shoulder in Port Magpies' trial game and will need to complete training on Wednesday to prove his fitness.
Motlop is unlikely to be recalled after a disappointing performance for North Adelaide, but Cassisi denied speculation the 29-year-old was on the outer at Alberton.
"Motts hasn't lost the total respect of the players. We set some high standards and a lot of those things are based around Monday to Friday, preparing properly and doing the right things to give yourself every chance of playing on the weekend," Cassisi said.
"Motts didn't meet a few of those standards. They're not major things, but they're things that we value.
"He's a goalkicker and he puts pressure on in our forward line. We want nothing more as a playing group than to have him in our side. He understands that and we look forward to him turning it around this week…and hopefully he'll be up for selection."
Port Adelaide will have the advantage of an extra-day's break over the Eagles, who played in stifling conditions at Patersons Stadium on Sunday afternoon.
Cassisi said the club was hoping to attract a big crowd at AAMI Stadium to watch the Power and Port Magpies play in a double-header for the first time as one club.
"The win is vital for us. We set ourselves to win at home and it really helps our season if we win a lot of home games," he said.
"To have both teams out there on the same day representing the one club is a special occasion. Hopefully, the Maggies have a win and we can back it up afterwards."
