But Roy Hodgson is ready to give him his first England call-up, according to reports.
The 45-year-old, who also played for the Saints, believes Shaw is developing into a left-back of real promise.
However, Le Saux feels the 18-year-old's progress is the most important aspect of his career right now - and for that, Shaw must resist a move to Stamford Bridge and stay at Southampton.
"I've been watching him play quite a lot," the Blues legend told Press Association Sport.
"He has the qualities of an attacking full-back who has a lot of pace and a lot of energy.
"His defending is getting better as he gets more experienced.
"He's still very young and the more experience he gains for his club and at under-21 level, I feel that he's in the right place at the moment and his development is crucial."
One man who does reportedly feel Shaw is ready for a step up, though, is England boss Hodgson.
Indeed, the Daily Mail claim that the Three Lions coach is ready to call the 18-year-old up to the senior squad ahead of their friendly against Denmark on March 15.
Intriguingly, the decision might lead to Shaw taking Ashley Cole's place in the national side, something that could be a long-term development at Stamford Bridge if the left-back is to eventually make the move to Chelsea.
Is Le Saux right about Shaw or should he join the Blues this summer?
image: © Ben Sutherland