The tech giant has announced the inventory of the handsets is "completed" and they will no longer be selling the midrange devices on the Google Store.
In a statement issued to The Verge, Google said:"Google Store has sold through its inventory and completed sales of Pixel 3A.
"For people who are still interested in buying Pixel 3A, the product is available from some partners while supplies last."
It comes as Google is preparing to launch the Pixel 4A - the follow-up to 2019's Pixel 4 phone - and the device is set to go on sale for around $399.
Late last year, the company updated the Pixel 4's Face Unlock feature to allow the smartphone to "recognise" the owner's face "better over time" thanks to an improvement in the Pixel Features Drop.
Google stated: "When it's on, face unlock images are occasionally used to create improved face models.
"This helps recognise you better over time."
The Face Unlock works even if a person has their eyes closed.