On Sunday, Collingwood president Eddie McGuire described the decision to allow a clash between Australia and Argentina to be played on Saturday, September 14 at Patersons Stadium as an "act of treachery".
There is the potential for Fremantle to host Collingwood or Port Adelaide in the second week of finals on Friday, September 13, meaning the Magpies or Power would need to travel on a six-day break.
Collingwood is also preparing for Saturday night's clash against the Power on a six-day break.
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Demetriou said it was an extremely frustrating scenario that compromised the AFL finals series, and he understood McGuire's comments.
"This is a decision that was made by the West Australian Football Commission to host a rugby union game on a Saturday night smack bang in the middle of our finals," he said on Monday morning.
"It was a decision the football commission shouldn't have made.
"It is true that once that game was stuck on that Saturday night, that limits our opportunities to only play on a Friday night or a Sunday night.
"So it actually has a flow on effect. We're not happy with that decision."
Collingwood's elimination final against Port Adelaide could only be played on Saturday this week because of the Patersons Stadium situation.
The AFL could have faced a nightmare fixturing challenge had West Coast made the finals, as was expected at the start of the season.
"Unfortunately we could be in that same position next year," Demetriou said.
"I understand there is a contract in place the football commission has entered into for another [rugby] game during September, so we will face that issue again."
Demetriou said the AFL would need to appeal to the Australian Rugby Union in 2014 and ask the code to move its planned match next September, given that a contract is in place.
He said he did not blame the West Australian Government for the clash.
"The footy commission made the decision … they should know better," he said.
"The State Government, I don't think they're involved in this.
"The State Government's been very good to the AFL. They're great supporters of the game."
Twitter: @AFL_Nathan
Demetriou said it was an extremely frustrating scenario that compromised the AFL finals series, and he understood McGuire's comments.
"This is a decision that was made by the West Australian Football Commission to host a rugby union game on a Saturday night smack bang in the middle of our finals," he said on Monday morning.
"It was a decision the football commission shouldn't have made.
"It is true that once that game was stuck on that Saturday night, that limits our opportunities to only play on a Friday night or a Sunday night.
"So it actually has a flow on effect. We're not happy with that decision."
Collingwood's elimination final against Port Adelaide could only be played on Saturday this week because of the Patersons Stadium situation.
The AFL could have faced a nightmare fixturing challenge had West Coast made the finals, as was expected at the start of the season.
"Unfortunately we could be in that same position next year," Demetriou said.
"I understand there is a contract in place the football commission has entered into for another [rugby] game during September, so we will face that issue again."
Demetriou said the AFL would need to appeal to the Australian Rugby Union in 2014 and ask the code to move its planned match next September, given that a contract is in place.
He said he did not blame the West Australian Government for the clash.
"The footy commission made the decision … they should know better," he said.
"The State Government, I don't think they're involved in this.
"The State Government's been very good to the AFL. They're great supporters of the game."
Twitter: @AFL_Nathan
