Leading sports performance consultant Ray Wilson has stressed that this pre-season break could be pivotal in Luke Shaw's career at Manchester United.

The 19-year-old arrived at Old Trafford from Southampton for £30m 12 months ago, but despite much expectation, injuries and a lack of fitness limited the left-back to just 20 appearances in all competitions last term.

Asked what Shaw can do to improve his fitness record during the upcoming 2015-16 campaign, Wilson, who has worked with the likes of Danny Rose and Nacer Chadli at Tottenham Hotspur, insisted that the England international must look at his "whole physiology".

"Luke Shaw should have been working throughout the whole of the summer on the injury dysfunctions that hindered him last season. Working on his upper body strength, his muscle intensity, looking at his whole physiology," he told 888sport.com.

"So, when he walks through the door for pre-season his chest is out high making people remember why Manchester United bought him. Not 'Will he be fit? Will he feature?' He needs to quash all those doubts from early July."

Recent reports suggested that Shaw returned to training a week earlier than many of his United teammates.