The 21-year-old defender suffered a double leg break last season, with a long road to recovery leading him back to the first team fold.
Shaw has had to prove himself all over again under new coaching staff at Old Trafford, with Mourinho needing to be convinced that he is deserving of a regular role.
He is yet to see enough to suggest that the youngster is ready to be a prominent part of his plans, with there an element of trust that needs to be established.
The Portuguese tactician is, however, prepared to give Shaw time and has once again sought to bring an end to the ongoing rumours claiming that a sale could be sanctioned in the summer.
“Not just from the physical point of view, but also by the mental impact. So this season he has had a couple of small injuries and he needs to adapt.
“He knows what I like in a defender, he knows that I like stability, that I don’t like mistakes, that for me it is to trust a player totally and he has to work to get it.
“And when he is on the pitch again he has to try to give me that step by step because he is still only a young player, sometimes people forget he is only a young player with a lot to learn but I like the player and I like the boy.
“No, he will be here for sure, that is out of the question.”
Shaw has made just 14 appearances in all competitions this season, with only one of those coming in 2017 – against Wigan in the FA Cup.