For the first time since the IRB World Rankings began, the top 20 teams in the world will all be playing matches during the November Test window.
Friday's Ravenhill clash is an eagerly-awaited one, with the Tongan side ranked 15th in the world and Ireland 'A' playing for the first time since they won the Churchill Cup in the summer.
Tonga assistant coach Brian Melrose, the former Australian Under-20 and Sevens coach, has been brought on the tour to help put attack and defence structures in place within the backs division.
He said: "I was just appointed to the squad three weeks ago, and this time in Belfast has been the first opportunity I have had to work with the players.
"It has been a busy few days with a lot of constructive work being done on the pitch. The team, as a whole, are a big physical side, with powerful ball carriers and a very strong defence.
"It is difficult to pinpoint any individual player at the minute, but from my initial work with the squad, the back row of Vahafolau, Fono and Filo look to be a useful unit and work well together.
"The skipper, second row Kelekolio Paino Hehea, is a very solid and powerful player.
"In the backs, the New Zealand-born out-half Kurt Morath has a lot of talent. Vaka, the inside centre, is a big ball carrying runner.
"The full-back Filimone Lilo and right winger Alipate Fatafehi are both real prospects for Tonga.
"The game on Friday night will be a massive challenge. Irish rugby is on a high and the provincial teams are all playing well.
"We are expecting a very tough game, but are really looking forward to the experience," he added.
TONGA (v Ireland 'A'): Vungakoto Filimone Lilo; Latu Nagashima Alipate Fatafehi, Sukanaivalu Hufanga, Joseph Vaka, Poakikaifano Vakaloa; Kurt Morath, Kilifi Fangupo; Toma Toke, Semisi Telefoni, Mosese Moala, Kelekolio Paino Hehea (capt), Emosi Kauhenga, Seti Filo, Uelenitoni Fono, Samiu Vahafolau.
Replacements: William Mosaati Hafu, Po'alo'i Taula, Penisimani Fakalelu, Lisiate Faaoso, Rodney Mahe, Mahe Fangupo, Raymond Pierre Hola, Manu 'Ahota'e'iloa.