Forwards coach Robin McBryde says Wales will not make the mistakes of past Friday night autumn Tests when they face Tonga in Cardiff.
The Sea Eagles are the only Pacific Islands team not to have beaten Wales, who have lost to Fiji and Samoa at World Cups.
Fiji also earned a draw in Cardiff in autumn 2010 and Samoa beat Wales there in 2012 - both on Friday evenings.
"We have changed the way we've prepared for this game," said McBryde.
"We've been able to manage the squad a little bit differently with regards to spending a bit more time on the detail a little bit earlier in our preparations."
McBryde's fellow assistant coach
But McBryde is equally wary about their chances of sending Wales into their 30 November clash against Australia on the back of a defeat.
"We have got to be on our guard," said McBryde.
"Anyone who saw Tonga's game against France on the weekend knows how much of a threat they can be, especially when they are still in the game.
"So it is a big game for us, an important game, important for individuals and as a squad as well."
Newport Gwent Dragon Hallam Amos, a medical student, makes his debut among 11 changes to the side that beat Argentina 40-6 with only Leigh Halfpenny, George North, Rhodri Jones and Justin Tipuric surviving.
"Regarding Hallam, it is just a case of him getting out there and showing what he can do," said McBryde.
"At regional level we have seen glimpses of that. He is a great runner with the ball in hand.
"No doubt he will be tested, but that's international rugby.
"We saw the same thing last week with regards to [prop] Rhodri Jones and [centre] Cory Allen coming into the team and benefiting from having experienced individuals around them.
"I don't expect it to be any different for Hallam. Undoubtedly he has got the potential.
"It is just a case of delivering on Friday night. He has shown up well in training, so we are really looking forward to watching him."