The £31m defender bought from Benfica has failed to appear in any of United’s four Premier League games.
And Mourinho has admitted the 23-year-old needs to time to get used to the English game.
Despite his age, Sweden star Lindelof is experienced though with European and international football.
United have prioritised Eric Bailly and Phil Jones at the back so far this season.
However, Mourinho has confidence Lindelof can cope with the demands of Basel tomorrow (7.45pm).
“I think it is easier for him to play in the Champions League,” Mourinho said.
“There is no need for him to adapt to Champions League.
“But he needs a bit of time to adapt to the Premier league especially the new Premier League.
“He is very bright and very clam and step by step he will be there.
“I am more than confident for tomorrow, he is a very good player with a very good potential.”
Lindelof looked shaky in the 2-1 UEFA Super Cup defeat to Real Madrid last month.
But the centre-half has a chance tomorrow to show Manchester United fans what he can do when he makes his Old Trafford debut.
