The consumer brief follows the agency, which replaces Tea & Cake PR, being approached by the client.
It will involve day-to-day media relations in the UK, as well as activating its associations with governing bodies, the British & Irish Lions and ambassadors.
This includes messaging on the heritage and quality of Rhino products, with a Rhino rugby ball to be used during the Barbarians v Lions fixture that takes place in Hong Kong on 1 June.
The brand’s new contact suit will be also used by the Lions in training for the tour, which takes place in Australia in June and July.
It is understood that initial activation by Mercieca will focus on working with the brand’s ambassadors.
Mercieca PR director Gemma Oakes said the agency was ‘looking forward to helping Rhino Rugby tell its story during the coming months’.
The account is the third sports win for the agency for PR support in recent months, further to appointments from Legends Rugby and Mitre.
The Lions squad is made up of selected professional rugby players from across the UK and Ireland.