The Reds' no.23 sustained another head injury in the 4-1 defeat against Watford on Saturday and did not travel with the squad as a precaution surrounding the nature of the problem.
Shaw was substituted around the new Premier League ruling surrounding concussion protocols, being replaced by Diogo Dalot with six minutes remaining at Vicarage Road.
Carrick provided an update on the England international, stating to BT Sport: ''Luke had concussion a couple of weeks ago [during the Manchester derby against City] and then got another knock, so we just need to assess him as a precaution.''
With Carrick making four changes in southern Spain this evening, another omission from the side was playmaker Bruno Fernandes.