Spanish newspaper El Pais said Guardiola, 44, would stand as the last candidate on the electoral list for the pro-independence alliance planning to run in the election in September.
Being the last name on the list would make him unable to win a seat in the regional parliament, El Pais said — but the former player and coach would be a powerful talisman for the independence movement.
He led Barcelona to domestic and Champions League glory as coach of the club, one of the most powerful institutions in the region.
Guardiola has several times publicly displayed his support for the drive to make Catalonia break away from Spain. He flew over from Munich last November to vote in a symbolic non-biding ballot on the issue held by regional leaders.
Spain's national government fiercely opposes independence for Catalonia and has mounted court challenges against regional president Artur Mas's attempts to organise a full referendum.
Now left- and right- wing leaders in the rich northeastern region want to hold a regular regional election on September 27 to serve as a de facto plebiscite on independence.
Mas's centre-right CDC party and the left-wing ERC sealed a pact last week to run on a joint ticket in favour of independence, along with leaders of the influential pro-independence civil groups ANC and Omnium.
The parties agreed that if they jointly win a majority, they will form a coalition government that will aim to achieve independence within 18 months.
They were due to formally present their list of candidates later on Monday.