The Brazilian's race crash looked like a carbon copy of one he had in final practice which he said was caused by the front wheels locking after he braked and hit a bump on the pit straight before the Sainte Devote corner.
However the Italian team said Sunday's was different.
"The findings validated the first impressions of the engineers, confirming that the accident was caused by an element of the front left suspension breaking," they said on their website (www.ferrari.com).
Massa's car first hit the metal guardrail and was then pitched nose first into the energy-absorbing barriers. The driver was put into a neck brace on the spot and taken to hospital for precautionary checks.
Ferrari said Massa would need a few days' rest but was already preparing for next week's Canadian Grand Prix in Montreal and his presence there was not in doubt.
"The best news to come out of Monaco weekend is that Felipe is fine," said team principal Stefano Domenicali after a tough grand prix that saw Ferrari's title contender Fernando Alonso start sixth and finish seventh.
"Two big accidents, just over 24 hours apart and all he has to show for it is a bit of muscle pain."