Sanchez joined United from Arsenal in a swap deal involving Red Devils outcast Henrikh Mkhitaryan on Monday, but Belgium global De Bruyne explained that City would move on from the saga and not let it affect them.
Arsenal fans were given a painful of deja vu with their star man following in the footsteps of Robin van Persie who swapped the Emirates Stadium for Old Trafford in 2013.
Having finalised his move to United, he's in line to make his debut in their fourth-round FA Cup tie at Yeovil on Friday evening.
Mourinho went onto praise the evolution of players like Martial before underlining the important of his front five - consisting of the France worldwide, Rashford, Mata, Lukaku and Sanchez.
"I think he'll be very important for us because we want to have the best players possible", Mourinho told reporters. "If the player one day are on the bench and don't like it, I am happy with that". "I am not happy with Mourinho's decision not to play him, but it is his club, his team, he knows what he wants".
'United and Arsenal made a fantastic deal, I lost a fantastic player, Mr Wenger lost a fantastic player, Alexis changed from a fantastic club to a giant club and Mkhi changed for a fantastic club, so was a great deal for everybody.
Alexis Sanchez Arrives At Carrington For Medical Ahead Of Man Utd Move
Manchester United boss Jose Mourinho will want two more midfield signings after wrapping up a deal for Alexis Sanchez . Earlier Sunday, Sanchez posted a video on Instagram showing him walking across an airstrip towards a private jet.
Alexis Sanchez has blasted former Arsenal players after his exit from the club. "I will do my best to assist them as well", he said.
Diego Forlan, one of 15 South Americans to have played for the Red Devils, is excited for Sanchez.
Mourinho did express some regret that Mkhitaryan failed to live up to expectations, though he has no doubt Arsenal have got themselves a capable player. "He has now one-and-a-half years in England now, he adapted and he knows the way Arsenal play, the way they think".
"I am really honoured and proud to be Manchester United manager", he added.
'Could he perform better with us? Maybe. Could he also have given more to try to adapt to us? Could I take more from his talent?
Manchester United have won three previous meetings with the Glovers - all of which came in the FA Cup - and scored 13 goals without conceding in the process.