THERE is concern that extreme heat during the NAB Cup could be worsened by the trial of interchange restrictions.

Clubs are bracing for more hot conditions after St Kilda, Port Adelaide and Adelaide played in near 40-degree temperatures at AAMI Stadium on Sunday.

St Kilda coach Scott Watters was the first to raise the heat after his team’s games, describing the conditions at the ground as “pretty tough.”

“We have to have a close look at the heat policy, I mean that was pretty hot,” Watters said post-match.

"The only adjustment was two extra water carriers today, those players were under a fair bit of pressure in the second half.

"We tried our best to rotate them, but at the end of the day when you're playing in that sort of heat it's testing, particularly for younger players."

Port is set to bear the brunt of the hot weather during the remainder of the NAB Cup, with games to come in Renmark and Alice Springs.

As well as the Power's clash with Melbourne in the South Australian Riverland, the League has afternoon matches scheduled for a number of potentially hot places in coming weeks including Townsville, Perth and Mandurah, south of the WA capital.

From round two of the pre-season competition clubs will be forced to contend with the standard three players on the bench, plus a substitute, and a cap of 20 interchanges each quarter.

Port's football manager Peter Rohde admitted his players face a challenging pre-season.

"It's going to be difficult to manage if you've got really hot weather in Renmark and Alice," Rohde told AFL.com.au.

"When the draw came out we were disappointed we were playing in regional towns twice in a row, and then add the hot weather.

"I think the real issues are going to come in the next few weeks when you're only allowed three interchange and the sub, plus a cap of 20 per quarter."

The AFL has left open the door to making concessions for the heat as the pre-season continues.

"For remaining matches in the NAB Cup, we monitor the conditions for every game, and will continue to do so, if we need to make changes at any venue," spokesman Patrick Keane said.

The League is adamant it didn't make the wrong call before Sunday's matches at AAMI Stadium, pointing to larger squads and benches and the shortened match format of the NAB Cup.

"It was hot, but we were comfortable with how the day had proceeded and the clubs were kept fully informed in the lead-up to the game," Keane said.

"Our clubs do have outstanding support staff to assist players and players have been training for some months through the summer period."

Most immediately, the League is likely to avoid any dramas in Sydney's west, with only 27 degrees forecast for this coming Sunday's triple-header featuring Greater Western Sydney, Sydney Swans and Carlton at Blacktown.

Potential hot spots

Saturday March 2
Gold Coast Suns v North Melbourne – Townsville – 3.30pm
Essendon v Richmond – Wangaratta – 5.10pm

Sunday March 3
Port Adelaide v Melbourne – Renmark – 4pm

Saturday March 9
Fremantle v Western Bulldogs – Mandurah – 3.30pm
West Coast v Port Adelaide – Alice Springs – 7pm