The national body has compiled a seven-page submission for Messara ahead of his review, being finalised in the coming weeks.
The Otago Daily Times reported yesterday that Racing Minister Winston Peters had requested that Messara's review specifically target thoroughbred racing.
It was previously thought it would equally assess all codes.
The review will incorporate all codes in some form, but how much harness racing and greyhound racing will be analysed is unknown.
HRNZ chief executive Edward Rennell remains confident his code will get a fair hearing from Messara despite the recent revelation thoroughbreds could be the big winners from the review.
''We are confident Mr Messara is very professional and will review things from an overall industry perspective. We have had constructive dialogue with him and have made a submission to him,'' Rennell said.
The submission told Messara of the recent decline of harness racing and its battle to maintain its relevance.
''The issues facing racing globally are similar and can be summarised as declining relevance within the mainstream public,'' the submission said.
''This impacts on all levels of the industry and strategies are required to address this.
''Harness racing in New Zealand ... is in decline and facing numerous challenges.
''Participation levels have reduced, reflecting the challenging economic environment facing the industry.''
HRNZ told Messara one of the best ways to strengthen its industry was to look after owners and punters.
''In HRNZ's opinion, the two key value drivers are owners and punters. Improve the value proposition for these two groups and benefits will flow to all other industry participants and sector groups.
''HRNZ's business plan and activities are developed with this philosophy in mind, which we believe is equally applicable to the NZRB [New Zealand Racing Board] and other codes.''
HRNZ also suggests the racing industry must work to regain its relevance with the public.
''Racing in New Zealand must strive to re-establish its relevance in mainstream thinking.
''Appealing to younger generations when there are so many other entertainment options is another major challenge the industry needs to develop more effective strategies on.''
HRNZ has not recommended sweeping change to racing industry bodies and has largely endorsed the NZRB's strategies.
It has backed a move for the TAB operator to possibly outsource its betting operation, and asked Messara to recommend the race fields legislation be passed as soon as possible.
New Zealand Thoroughbred Racing will not be making an official submission to Messara. It said it had had a number of discussions and Messara had been a ''very good listener''.
Greyhound Racing New Zealand did not respond to an inquiry about the submission it planned to send to Messara.