MANCHESTER, England — Manchester United manager Jose Mourinho has described the second leg of his team’s Europa League semifinal against Celta Vigo on Thursday as “the most important match of our history.”

United, a three-time European champion and 20-time English champion, leads 1-0 from the first leg in Spain last week.

The winner of the Europa League earns a place in next season’s Champions League, increasing its significance for a United side that has only played in Europe’s top competition for one of the last three seasons.

“For Celta, it’s — in their words — the most important match of their history,” Mourinho said Wednesday. “My feelings, it’s also the most important match of our history. It doesn’t matter what happened before, how big the matches we played before.”

“I don’t believe Celta dreams more than us, wants (to win) more than us,” Mourinho added. “I really don’t believe. In this aspect, I don’t think there will be a difference between both teams.”

Mourinho has played weakened teams in recent Premier League matches, despite United still being in with a chance of a top-four finish and gaining Champions League qualification via that route.

It seems that for Mourinho, it’s Europa League or nothing.

“The situation is simple: 17 matches in seven weeks, with 16 players, is impossible,” Mourinho said. “It’s not a gamble, it was a simple decision, a decision based on common sense and a consequence of our situation.

“We are giving everything we can, the players, myself, everyone. We are giving everything so when you give everything, no problem.”

The Europa League is the only major trophy that United hasn’t won — and might be the last one captured by the club’s captain, Wayne Rooney.

Rooney committed his future to United in February amid interest from Chinese clubs, while Everton manager Ronald Koeman has also stated he would be keen to sign the England international.

However, Rooney is no longer a first-choice player at United and has only made 22 starts this season, fueling the belief his future lies elsewhere.

“I haven’t thrown my toys out of the pram. I haven’t made a big fuss of it,” Rooney said.

“But of course I’m a football player, I want to play football and the more I can play obviously the better for me and the more I feel I can help the team.”

Ajax leads Lyon 4-1 going into the second leg of their semifinal in France.