The Liverpool duo, who enjoyed an extended break due to their respective international commitments earlier in the summer, are set to join up with their teammates as preparations for the 2017-18 campaign continue.
Coutinho and Lallana's returns will leave Emre Can as the only member of Jürgen Klopp's squad yet to start pre-season training.
Can will be back later in July following his participation in Germany's successful Confederations Cup campaign.
We'll once again bring you live coverage from Melwood on Tuesday, so keep an eye on Liverpoolfc.com for exclusive, behind-the-scenes pre-season content you can't see anywhere else.
The Reds will take on Tranmere Rovers in their first pre-season friendly on Wednesday (7.45pm BST kick-off).
LFCTV and LFCTV GO are the only places you can watch all of Liverpool's pre-season games: For more information and details on how to sign up for either service, click here.