They emigrated to New Zealand from Tonga as teenagers to advance their rugby careers, and it will be the first time they have played professionally in their homeland.
But they know most of the home crowd's support will be for the Moana Pasifika side, which is representative of the country. They have also recently had players in Tonga doing promotion work for the game, the first the country has hosted.
Ma'u said, "I never thought this would happen, having a rugby team in Tonga but that was always my dream; to make it in rugby, make my family proud and to inspire little kids. I'll try not to get too emotional when we get back home and focus on the game and our game plan."
It would be an example for young players in Tonga to know they could achieve anything if they worked hard for it.
Fakatava said, "This is a bonus for us. They love rugby and being the first time in Tonga it's going to be massive. It's going to be a packed stadium and the King is going to be there."
They were both concerned that having spent so much time in Dunedin, it might be harder to adapt to the conditions in Tonga, where it is expected to be hot for the game.
Prop Ethan de Groot, who is on All Blacks leave, and Rhys Patchell, who was confirmed to be out for the remainder of the campaign due to his pectoral strain, will be missing from the game.
Cameron Millar has been given the starting role at first five-eighths, and coach Clarke Dermody said his performance in last week's win over the Rebels showed his development.
"He's done a great job and we've got confidence in him. He's got a big future. It won't be easy, but he's tracking the right way.
Dermody said while there were errors, the side had executed the team plan against the Rebels. There were still issues in the attacking 22m, but they concentrated on playing for each other and setting people up this week.
The side was excited about playing in Tonga and wanted to do well for Ma'a and Fakatava.
"They're going home to play in front of their families, so we want to make that as memorable for them as we can and our part in that is playing well."
