Mourinho told Sky Sports: "Yeah, all [focus] on the Europa League but today we tried to play for a result. You can tell me you didn't play with the best team, the players who are the first choice at the moment, but you cannot say we didn't try to win the game".
A 1-0 win at Balaidos last week means Manchester United are in pole position to reach the final of the Europa League for the first time in the club's history but Celta are yet to give up.
"The situation is simple". "17 matches in seven weeks, with 16 players is impossible". It was not a gamble, it was a simple decision, a decision based on common sense. I think Jones, Smalling, Mata were incredible, the way they performed after seven weeks of being out.
"We lost because we didn't score and we had great chances to score before them".
"It was not a gamble, just an outcome of our situation". "I tweeted during the game that it was like a testimonial, and it was certainly played at that kind of pace - which is what you would expect from a pre-season friendly between two Premier League teams played in the United States".
"In terms of motivation we are even", said the Portuguese, who led Porto to glory in the UEFA Cup -- as the Europa League was formerly known -- in 2003. It's more important than finishing fourth.
After months of being easily irritated, angry and frustrated with certain aspects of the season including injuries and a lack of goals from his players, it seems as though he was in a more jovial mood on Sunday as he mocked his long-time rivals as they finally celebrated a win over him. Our chances were the big chances of the match. "I think this game will be open and perhaps we will see more opportunities for them and for us". "You become cleverer, and since my (last) red card, I think things have improved".
Speaking at the press conference before United's Europa League semi-final against Celta Vigo, Rooney reiterated his desire to remain the club he signed for from Everton in 2004.
Mourinho said after falling to his first league defeat to Wenger in their 13th clash that it would now be "impossible" for the Red Devils to finish in the top four.
"For example, the match against Chelsea (which United won 2-0), I could feel they (the fans) wanted to play". "It's the first time I leave Highbury or Emirates and they're happy". Will he prove to be one that got away from Old Trafford while United's eyes were fixed on more dazzling - and expensive - prospects? "Against Anderlecht it was not warm enough".
"And it was because it was a quarter-final second leg".
"Trophies are very important for the club, and it is very important to be in a European final. So we have to fight hard tomorrow".
The likes of former Arsenal winger, Marc Overmars and ex-Germany global, Michael Zorc, have been linked with a director of football role at the North London club, with the pair now filling that position for Ajax and Borussia Dortmund respectively.