He has been heavily criticised by Jose Mourinho after his team suffered their third straight loss across all competitions.
The Times recently reported Shaw had played through the pain barrier of his groin injury at Vicarage Road.
Mailsport reporter Jack Gaughan claims the 21-year-old will be undergoing a scan today to review the extent of injury.
Shaw missed out on the majority of last season as a result of a horrible double fracture, but has hit the ground running under Mourinho and has been one of our best players so far this campaign.
His hard work seems to have aggravated a chronic groin problem during the game on Sunday, leading to his mistake which gave Watford their second goal of the match.
He has worked tremendously hard to make a full recovery and cement his place in the starting XI within a year of the incident, hopes are the new concern is nothing serious.