The Portuguese head coach was sacked by the Red Devils back in December after Manchester United endured a tough start to last season and were struggling to find consistent form.
The Red Devils moved quickly to bring in Ole Gunnar Solskjaer as his successor, and the Norwegian has since been handed the job on a permanent basis.
Mourinho cut a frustrated figure both on the touchline and in front of the media during the final few months of his time at the Old Trafford outfit.
And the Portuguese coach has now underlined that he feels some of his success at Old Trafford was undervalued, especially after he led them to a Europa League and League Cup double in his second season in charge, and a second-placed finish in the following campaign.
Speaking in an interview with Sky Sports, Mourinho said: “I can just say that the Manchester United time was not an easy time. I always felt that to win the Europa League was fantastic and it didn’t look like it was, the way people approach it.
“To finish second was even more than that [success], so probably I was feeling a little bit like: ‘Wow, I’m working well, I’m giving everything and I’m not getting what I think that deserves’.
“The only thing I can promise you is that when I have the next club, the next project, I will be so, so happy that I will walk into that press conference with a big smile. That I can promise.”
Manchester United are currently preparing for their Premier League season opener against Chelsea FC at Old Trafford on Sunday 11 August.
The Red Devils finished sixth and without a trophy last term after Solskjaer was brought in as Mourinho’s successor back in December.
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