"I just think that he was very clear by showing what he did past year was not enough for him", Mourinho said in a press conference ahead of the first English Premier League (EPL) match this season against West Ham United.
The former Sweden striker was United's top scorer last season, hitting 28 goals as they won the Europa League, the League Cup and the Community Shield.
With Champions League football back at Old Trafford this season it appears that Mourinho is determined to use any possible artillery to achieve his and the club's goals.
He has trained with the club during his rehabilitation, though, and Mourinho has made clear he still believes the forward can do a job for him.
"You know he's injured, he needs time to recover, he's not ready to play tomorrow", Mourinho said. Is the former PSG man ready to play second fiddle? It's not something that's urgent, it's not desperate to have it done or not.
Manchester United have been linked with a host of players so far this summer but the Red Devils have so far only concluded deals to land Victor Lindelof, Romelu Lukaku and Nemanja Matic so far.
Manchester United were beaten 2-1 by Real Madrid in the Uefa Super Cup on Tuesday night as they missed their first chance to win a trophy this season.
Mourinho told a news conference on Friday: "We have 25 percent left which means one of four - we got a central defender that can play many other positions which is very important".
"Between the players we have lost and the players we have got, I think we are in a similar situation but with more experience of working together and a much better pre-season". I don't think I am in a position of moaning, crying, contesting or to say I am not happy with it.
"We have had a better pre-season than a year ago and we have the confidence levels of a team that has won a European competition and returned to the Champions League".
He continued: 'I'm happy with the effort the club did, I'm happy that the club managed to do 75 per cent of the work before the Premier League starts.