The 28-year-old was included in the original squad for the tournament, which takes place from 1-10 June in Solomon Islands capital Honiara, but has now been ruled out after fracturing his arm while playing for Lautoka in the Vodafone Fiji FACT semi-final against Ba.
In a double disappointment for Hassan, he also saw his side’s Fiji FACT dreams come to an end as the Blues lost 1-0 at Govind Park.
There was happier news for fellow national team member Samuela Vula, who starred for Suva as they beat Ba 1-0 in the final to end a 17-year wait for a major trophy.
The defender is likely to miss out on this week’s celebrations though as he has been summoned to return to the national squad’s training camp in Ba.
Hassan will not be the only name missing from the first squad announced by coach Carlos Buzzetti when Fiji travel to Honiara for the Nations Cup next Tuesday.
Goalkeeper Akuila Mateisuva, custodian for the U-23 national team that nearly qualified for the London Olympic Games, and midfielder Ilisoni Tuinawaivuvu have also dropped out as Buzzetti reduces his numbers to a final line-up of 20.
Fiji have been drawn in Group B and will do battle with Solomon Islands, New Zealand and Papua New Guinea while Group A consists of New Caledonia, Samoa, Tahiti and Vanuatu.
The teams will take part in a tournament based on a league system with semi-finals and a final and the winner will go on to represent OFC in the 2013 FIFA Confederations Cup.
The four highest-placed teams will then contest stage three of World Cup qualifying – a round-robin, home-and-away play-off series. The matches are foreseen to take place between 7 September 2012 and 26 March 2013 in FIFA windows.
The winner of the third stage will advance to an inter-continental home-and-away play-off against the fourth-placed team from CONCACAF – the confederation of North America, Central American and the Caribbean – for a place at the 2014 FIFA World Cup Brazil™.