The story, via respected radio station Radio Catalunya, statess that Ernesto Valverde is keen on bringing the Cameroonian international back to the club where he played as a youngster.
Onana, 22, signed for the Dutch side in 2015 – after five years as a youth team player at the Nou Camp – and he has impressed in over 100 senior appearances for them.
Onana would initially be brought in as back up to first choice keeper Marc Ter Stegen, with the potential to move ahead of the German in the pecking order should he continue his progression.
Valverde is reportedly open to letting current No.2 keeper Jasper Cillessen leave at the end of the season, with Dutch international frustrated with his limited first team opportunities behind Ter Stegen.
Cillessen is likely to miss the majority of the 2018-19 season run in due to injury, with La Masia graduate Ignacio Pena stepping in as deputy.
Alongside this, Valverde, and Luis Enrique before him, have only ever trusted Cillessen as their Copa del Rey keeper, with just two La Liga appearances in his three seasons at the club.
The former Athletic Bilbao manager could face a battle to convince Onana to return to the club who rejected him as a teenager, and his give up his No.1 jersey with Ajax, where he has been the first choice for the last three seasons.
However there is a strong potential that Onana may be swayed by the prospect of working as understudy for a season, before Ter Stegen completes his widely rumoured return to Germany to replace Manuel Neuer at Bayern Munich.
Alongside Onana’s own potential misgivings about swapping the Johan Cruyff Arena for a spot on the Barcelona bench, the Catalan side may also face competition from other European sides – who are in a stronger position to offer him first team football.
Impressive performances in the Champions League has meant that Paris Saint Germain, Arsenal, Tottenham and Bayern Munich have all thrown admiring looks in his direction.
If Ajax are to pull off a shock in the Champions League last 16, and beat Real Madrid at the Santiago Bernabeu, then Onana is likely to be at the forefront of it – which only increases his options and transfer fee.
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