"I haven't played against Jamie Roberts before, but he's a quality footballer," Mapusua said. "He's a big man, but he has got silky hands and is deceptively quick. Him and (All Blacks centre) Ma'a Nonu had a real good battle last weekend.
"Roberts is the guy to get Wales going forward, which is what he's good at, and alongside him Tom Shanklin is another quality player with great feet and great hands.
"We will have our work cut out, but in saying that, we will be going out to try to do what we do best. And dare I say it, try and entertain."
Mapusua also handed out praise to an unlikely recipient. "The player I'm really looking forward to coming up against is Gethin Jenkins. He pops up everywhere. He was great against New Zealand, making tackles that most backs would be proud of."
Samoa are attempting to throw off their reputation as a side who prefer carefree rugby to the more structured game played in Europe.
"We are trying to change our approach," Mapusua said. "People have a view of Samoa as being a side that likes to throw the ball around but lacks discipline and blows up long before the end of matches. Most of our side are full-time professionals and we have taken on board the value of preparation, such as conditioning and nutrition.
"We will never lose our core values and we will always prefer running to kicking, but we know we have to be smart rather than known as entertainers. It is frustrating for us because we very rarely play against one of the top sides. We would like a better fixture list and Friday gives us the chance to show that we deserve one."
Samoa: Lui (Apia); Lemi (Wasps), Williams (Clermont Auvergne), Mapusua (London Irish), Tuilagi (Apia); Fili (Wellington), Polu (Bay of Plenty); Va'a (Glasgow), Schwalger (Sale), Johnston (Toulouse); Levi (Newcastle), Tekori (Castres); Stowers (London Irish, capt), Treviranis (Apia West), Tuilagi (Perpignan). Replacements: Williams (Apia West), Taulafo (Tasman), Thompson (Dax), Faamatuianu (Bath), Mai (Apia West), Fa'afili (Leeds), Esau (Apia West).