VIGO, Spain -- Jose Mourinho says he is ready to rest key players in Manchester United's remaining Premier League games in order to boost the club's chances of emulating Juventus, Bayern Munich and Ajax as the only teams to win every major honour in the game.
United face Celta Viga at Estadio de Balaidos on Thursday in a Europa League semifinal first leg with the Old Trafford outfit aiming to win UEFA's secondary competition for the first time.
Only Juventus, Bayern Munich and Ajax have won all of UEFA's major competitions -- the Champions League, UEFA Cup/Europa League and the defunct European Cup Winners' Cup -- as well as being crowned world champions by winning the FIFA Club World Cup or its forerunner, the Inter-Continental Trophy.
But with United's resources being stretched by injuries during their congested fixture list, Mourinho says he must now choose between prioritising Champions League qualification through the Europa League rather than via a top-four finish in the Premier League.
And he says he will make wholesale changes against Arsenal this weekend, and in the final game of the season against Crystal Palace, if his team get a positive result on Thursday and then progress to the final in Stockholm on May 24.
"I know the Europa League is the only competition Manchester United as a club have never won," Mourinho said. "It would be great to close the circle and say we are a club that has won every single competition in the football world.
"Thinking about us as a team, I think it would be good, given all the problems we have, and would allow us to be back in the Champions League next season. We have to try, that's what we do.
"So the Europa League has become, for us, more important. Of course it depends on the result and the way we analyse the situation after the match, but if we have to rest players next weekend, we are going to that.
"And speaking hypothetically about a final, and obviously it would be premature to speak about the final given Celta has a 50-50 chance of qualifying, if we play the final, the players would not be selected to play the previous game on the Sunday."
Celta Vigo go into the game having dropped below halfway in La Liga due to coach Eduardo Berizzo resting players in recent weeks in order to prepare for the United tie.
And Mourinho says the home team have proved their determination to reach the final by fielding weakened teams in the league.
"When somebody arrives in the semifinals, they want to be in the final," he said. "That's normal.
"Europa League is a long competition, a team to be in the semifinal has to play in the group phase, has to play three knockout phases, has to travel a lot, so to arrive in the semifinal you want to be in the final. Celta wants, we want.
"Because of their situation in La Liga, a comfortable situation, they manage to think just about the Europa League, the best players in best condition, so a difficult match for us.
"I don't think they are coming just to enjoy the game. If that was the case, they wouldn't have played with the second team and lost 3-0 to [Athletic] Bilbao at the weekend.
"They played three games with their second team, so they are very much trying to win."