Depay is set for January departure after struggling to make an impact since his arrival from PSV last season, managing few minutes of playing time in the Premier League under Mourinho this season.
In total, the 22-year-old Netherlands international has only appeared in eight matches in all competitions and was last seen in United squad for the Europa League fixture against Feyenoord in November.
And Mourinho explained the reason why Depay has been on the sidelines in 2016-17.
“He was not playing last season. It was not that last season he was playing phenomenally and this season he is not featured at all. That’s not the situation,” Mourinho said.
“I have to say that in the past couple of months my decisions in relation to Memphis were influenced by the feelings and the information that he would like to leave in January and that we were going to have a real offer that we would be willing to accept. That influences me.
“If I know, if I have the feeling that a player is leaving – if I have to give chances and develop other players – then I go to [Jesse] Lingard, [Henrikh] Mkhitaryan, [Anthony] Martial, the players I know 100 per cent who are going to stay with us.
It is a position where we have more options.”