By United's calculations he had simply missed too much football through injury over the last three years - playing no more than 19 league games in each season.
Speaking yesterday, however, Mourinho revealed why Martial would not be starting against Leicester in their Premier League showdown at Old Trafford.
The club believe they have delivered over the course of the last two windows on the agreed targets with around £73m invested this window in Fred, Diogo Dalot and goalkeeper Lee Grant, as well £35m for Alexis Sanchez in January. As for United, the goal is to win the Premier League, and failing to get three points here will raise some big questions after just the first matchday.
Tottenham fans' transfer woes but Daniel Levy part of bigger picture
That is the reality that is for us is a massive challenge, because for us it never happened before and we need to be careful. Pochettino said he wanted to see his players "keep going" after the World Cup and to "feel the internal motivation".
It is understood United officials have grown increasingly tired and suspicious of Pogba's high-profile agent Mino Raiola, whom they blame for stories that his client would prefer to play for Barcelona.
Man Utd have registered victory in 17 out of 26 opening day fixtures they have played in.
'I am not confident, ' Mourinho (below) said of United's chance of new signings yesterday morning.
Tottenham achieved objective, says manager Mauricio Pochettino
Pochettino does accept how the lack of activity might be viewed externally, but is happy with the club's vision. "We finish the lodge at the training ground".
"My view is that first of all is hard for me to believe we finished second when I listen, when I read, not much but sometimes I do, it is hard to believe that we finished second because you [the media] are capable of making people that finish second look like they were relegated, and people who win nothing, finish below us, and you make them look like serial winners", Mourinho said.
United had seven players involved in the final weekend of the World Cup with Romelu Lukaku, Marouane Fellaini, Phil Jones, Marcus Rashford, Ashley Young, Jesse Lingard and Paul Pogba representing the club and set to return late. I don't know their identity right now, I don't know how they can dig deep and turn a losing position to victory and they style that they'll come out with. Having left the club's United States tour to attend the birth of his child, the French forward will now "start again", Mourinho said, with pre-season training.
"I have my players and I like my players", Mourinho said.
"A lie repeated 1,000 times is still a lie, but the perception of people is that it's true". He's a midfield player that technically is very good.
Unai Emery Needs To Make One Decision Before The Transfer Window Closes
Welbeck earns a cool £115,000 a week at Arsenal, so he could be moved on this summer to free up valuable funds. Further, Lehmann had to share his thoughts on Alisson Becker, Liverpool's new number one.