Bloom has a long-standing family commitment based around half-term week.
His absence from the Gtech Community Stadium on Saturday is sure to attract attention and speculation.
A well-placed source said he has been due to miss the fixture for some time due to a family event.
The Seagulls will aim to secure only a second league win since the end of November as they face a Bees side eyeing a European place.
Bloom usually goes in with the away fans when his side visit Brentford.
This dates back to trips to Griffin Park and saw him in the thick of it when away fans started voicing disapproval of a tactical substitution made by Fabian Hurzeler in last season’s fixture.
He also joined in prolonged applause for Enock Mwepu in the 2022-23 season when Albion visited Brentford in the first game after it was announced the midfielder would have to retire due to a heart condition.
There is currently unrest and division among Albion fans as their side slip in the Prem standings.
But the travelling contingent were supportive in defeat on recent trips to Aston Villa and Liverpool.