The midfielder has worn No.21 since joining the Reds from Arsenal two years ago but is set to change number this summer ahead of the next campaign.
Daniel Sturridge will vacate the jersey when he departs the club upon the expiry of his contract.
As a gesture to those who have already purchased a 2019-20 replica shirt printed with ‘Chamberlain 21’, Oxlade-Chamberlain will personally reimburse fans by way of a like-for-like exchange for a ‘Chamberlain 15’ jersey.
The offer applies to all shirts purchased in official club outlets and via the official LFC online store before midnight on June 5, 2019.