Samoa A are already in must-win territory for this afternoon's World Rugby Pacific Challenge clash against Tonga A in Suva.
The Samoans were stunned 34-31 by Junior Japan in the tournament opener on Friday.
Head coach Potu Leavasa said they only had one week to prepare their squad because they had been focusing on the Brisbane Global Tens.
He said new trial laws around the scrum, where the 'set' call has been removed, the halfback no longer required a signal to throw in the ball and one player from the team who put the ball in must strike for the ball, were not communicated to them until the day before their first match.
"That's another issue. They just let us know the short time about the scrum new law," he said.
"It's something that we need to get used to but only one day that we've prepared for that.
"Some of the forwards, front row, they're not happy about they way they informed them one day before the game but we have to get used to that new law."
Potu Leavasa said they did not stick to their game-plan against Japan and will need to be more disciplined against Tonga.
"Japan is the fittest team but we tried to play our game-plan, like tight" he said.
"Against Tonga it will be the same: when it comes to the Pacific it's always physical games and it comes down to our preparation but I think my boys will be ready.
"I know that Tonga will be - they need a win because they haven't beat Samoa A team for a long time."
The Samoan squad includes four Manu Samoa internationals: first five Patrick Fa'apale, Jeff Lepa, Talaga Alofipo and Ope Peleseuma, and Potu Leavasa said the Pacific Challenge was an opportunity for them to press their case for higher honours.
Defending champions Fiji Warriors beat Tonga A 38-30 in their opening match and host Junior Japan in the late match at ANZ Stadium.