The 25-year-old left-back has been one of the most consistent performers for Manchester United in the ongoing campaign.
His marauding performances at left-back have got him back into contention to be in the England squad for this summer’s European Championship.
The widespread belief is that Shaw has finally put his difficult past few seasons behind him and is finally ready to justify the big money Manchester United spent on him in 2014.
However, Nicol wants to wait before passing judgment on Shaw as he is keen to see how the defender reacts to another injury set-back.
He stressed that it would show whether the defender has learned from the mistakes he made previously.
Nicol said on ESPN FC: “The question is what is going to happen to Luke Shaw if he picks up an injury and is out for three or four weeks.
“Is he going to go back to the old Luke Shaw or has he learned from what he has been doing wrong in the first two or three seasons at United?
“It is very easy when you are playing well, you are fit, everything is working, you are ticking over nicely and you are winning games.
“The real test will come when he picks up an injury and misses three or four weeks and then we will see whether Luke Shaw has matured and learned or this is just a temporary fix.”
Shaw has featured 34 times for Manchester United this season and has beaten off the challenge from Alex Telles to establish himself as the first-choice left-back.
