Sanchez moved from Arsenal to Old Trafford in January, but had difficulty replicating his form in Manchester.
The Chilean scored only four goals in 28 competitions for the Red Devils in all competitions and only scored once in the season.
This is despite a recent upturn in United's form with manager Mourinho, who reportedly was close to the sack a few weeks ago.
A win against Juventus in the Champions League during the week seems to ease immediate concerns about Mourinho's future.
He is now on Sunday against Manchester City (16:30 clock) with a little more confidence in the Manchester derby.
Sanchez is a little doubt that this collision had to hold his thigh as he limped off the pitch against Juventus.
Whether he is fit or not remains to be seen, but reports suggest he was never Mourinho's first choice.
The Times claims Mourinho privately admitted that he would have preferred the Red Devils to sign Ivan Perisic in the summer of 2017.
The Croat shone during the World Cup when his nation reached the final, with rumors that United would soon be after him.
Mourinho believes that the Inter Milan star has better crossing abilities than Sanchez and that this would have been the key to providing service to people like Romelu Lukaku.
The Times also claims that Sanchez of Manchester United with PSG wants a desired destination for his departure.
He was recently taken out of the line by Mourinho, and Sanchez's former coach Arsene Wenger believes this was positive.
"It's the question he raised with his achievements," said Wenger to BeIN Sport.
"I think he lost his trust.
"The strength of Alexis Sanchez is to take the initiative to dribble, to accept the people.
"This type of player is most vulnerable when they are out of confidence because their game is based on trust and can feel free to take the initiative.
"He has slowly lost despite the interruption of the season. Since the beginning of the season, he looks as if he has a high level of energy, which he has also lost.
"Surely he is refreshed now because Mourinho has taken him out of the game for a while and he has a good chance to return to where he belongs as a top player."