Key will host Bainimarama atthe Bledisloe Cup game on Saturday at Eden Park.
New Zealand and the United States have tried to maintain a reasonable relationship with Fiji, not least to offset its growing friendships with China and Russia.
Fisheries and other trade will be a key focus of Bainimarama's activities in Auckland tomorrow as he seeks to drum up greater investment in Fiji.
Shane Jones, New Zealand's Pacific Ambassador for Economic Development, will host him for much of the day.
The pair will be speaking at an investment symposium in Auckland.
The Pacific trade and development deal Pacer Plus is also likely to be the agenda of talks with McCully tomorrow and Key on Saturday.
There has been some disquiet over the detention last month of five opposition figures who took part in a forum to discuss the country's constitution, although they were released without charge.
Jones, however, said: "Let's deal with the man as the elected representative of Fiji and the reality is that two-way business continued over the last 10 to 12 years.
"Anything that creates [fisheries] industry jobs in that part of the Pacific deserves our support. There is unfinished business in relation to Pacer Plus."
Bainimarama will have meetings with the Fiji community in Auckland. He will be formally welcomed to New Zealand on Saturday and hold formal talks with Key before the rugby.