At some point in all of the opening games of the NRL premiership this weekend, the teams will come to a shuddering halt. That is the stark prediction of Wests Tigers coach Tim Sheens, who reckons the combination of intensity of performance, hot conditions and reduced interchange will all combine for a second-half collapse.

This season the rules have been changed to allow only a 10-man interchange (instead of 12), a move designed to create more opportunities later in the game for the little men. But teams have been using unlimited interchanges during the trials and will face their first restrictions in replacing tiring players from this Friday night's Roosters-Rabbitohs blockbuster opener.

Wests Tigers play St George Illawarra at 3pm on Sunday at the Sydney Football Stadium, after the original ground, the Sydney Cricket Ground became unavailable because of cricket commitments.

"The SFS will not be as bad as the middle of the Sydney Cricket Ground, because the SFS is shaded by the grandstand later in the day," said Sheens. "It will be hot and with the increased intensity of the season finally starting and the 10-man interchange … all of a sudden the teams will come to a shuddering halt."

The Brisbane-Penrith match will be played at 1pm Queensland time on Sunday with the Broncos electing to wear their lighter away strip to minimise the heat's impact. The Panthers will be forced to wear their dark strip.