Shaun Edwards believes it is "vital" the Wales players are protected by referee Mike Fraser when they tackle big-hitting Tonga on Friday night.
The principal South Sea Island teams - Tonga, Fiji and Samoa - have all made unwanted headlines this autumn.
Tonga prop Sona Taumalolo was sent off after launching a flurry of punches at France forward Yoann Maestri when the countries met in Le Havre two days ago, while scrum-half Taniela Moa received a yellow card for elbowing Les Bleus hooker Dimitri Szarzewski.
On the same day in Italy, Fiji had a Test record five players sin-binned against the Azzurri and at one point in the first-half were temporarily reduced to 11 players, with Samoa centre George Pisi landing a six-week ban - he has now launched an appeal - for a dangerous tackle on Ireland wing Tommy Bowe 10 days ago.
While Wales assistant coach and defence specialist Edwards readily acknowledges the need for his own players to stay disciplined in all areas, he has welcomed New Zealander Fraser's appointment.
"One of the most important guys this week is the referee, and I am really pleased that Mike Fraser is coming over from New Zealand," Edwards said.
"If I am honest, the South Seas Pacific Islands have a real reputation, which was cemented a little bit on Saturday with the Fiji game and Tonga game, of some little bit of unsavoury incidents at times.
"It is really vital that we keep our discipline, but it is also vital the referee protects our players. That's why I am so pleased that he (Fraser) is coming over.
"I've seen him in the ITM Cup and he is a really good referee. I am sure he won't put up with any nonsense, because it is something that has occurred more than once.
"They are very vigorous, as you would expect. They are proud people, but as long as it's within the laws of the game.
"I think Saturday was a little bit of a reminder, both the Fiji game and the Tonga game, that it can boil over at times and it is vital that we, in particular, keep our discipline."
Wales have won all six of their previous games against Tonga, including a 51-7 success on the islanders' sole previous Millennium Stadium visit 12 years ago, and they should comfortably preserve that record despite head coach Warren Gatland making a number of anticipated changes.
Newport Gwent Dragons back Hallam Amos could make his Test debut, with 22-year-old Cardiff Blues centre Owen Williams expected to partner Ashley Beck in midfield, while James Hook is tipped for fly-half duties and starters up-front look set to include Ken Owens, Luke Charteris and Ryan Jones.
"You would expect some changes," Edwards added. "It is important we also develop players for the future.
"You can't just have a first XV, can you, which has been proven recently with the number of injuries we've had."
Wales insist their collective eye will be on the job this week, and not allowed to roam towards an appointment with Australia in 12 days' time.
The Wallabies brushed aside Ireland two days ago, scoring four tries on route to a comprehensive success, although that has now been overshadowed by six players being suspended by coach Ewen McKenzie for next weekend's game against Scotland after they were involved in a late-night drinking session four days before facing Ireland.
One of the group - prop Paddy Ryan - will serve his suspension by missing the Wales clash.
"He is a new coach (McKenzie) coming in and he just wants to put his stamp of authority on it," Edwards said. "Maybe he asked them not to drink that week.
"I am sure at the appropriate time he lets them have a drink, but let's be honest, on the Tuesday before a Test match on a Saturday...
"I know we would be pretty disappointed if our lads did that. We don't really have an issue with that kind of thing at the moment."