MANCHESTER: Louis van Gaal was signing autographs after Manchester United's victory in the FA Cup on Monday when one voice from a group of mostly young fans wished the Dutchman the best of luck for the rest of the season.

"We need that," Van Gaal replied straight-faced, without looking up to the well-wisher. "Otherwise, I shall be sacked."

Barely a day goes by without fevered discussion about Van Gaal's future at Old Trafford, and it could be on even more shaky ground if United is eliminated by little-known Danish club FC Midtjylland after the second leg of the Europa League's first knockout round on Thursday.

United lost the first leg 2-1 in arguably the lowest point in Van Gaal's tenure.

Elimination would restrict the chances of United qualifying for next season's Champions League, with a place on offer for winning the Europa League.

The only other route for United would be to finish in the Premier League's top four and the team is in fifth place, six points adrift of fourth.

Being in the Champions League is likely a minimum requirement for Van Gaal if he is to stay on for a third season at United.

Anthony Martial's away goal at Midtjylland, which won the Danish league title for the first time last season, has given United a good chance of advancing to the last 16.

But an injury list currently containing 14 players, including captain Wayne Rooney, is proving a problem for Van Gaal with United playing three games in six days this week.

Title contender Arsenal visits Old Trafford in the Premier League on Sunday, and Van Gaal risks leaving his team fatigued for that match if he fields a full-strength lineup on Thursday.

He may, though, have little choice given the injury concerns.

In dominating the second half of the first leg, Midtjylland founded in 1999, the year United won the Champions League-Premier League-FA Cup treble during its glory days under Alex Ferguson showed it will be no pushover.

"Midtjylland are very well-organized, we have seen that in the away game," said Van Gaal, whose team was eliminated in the group stage of the Champions League. "But still everything is possible."

Here are some things to watch out for on Thursday:

TENSIONS IN MOSCOW

Lokomotiv Moscow's game against Fenerbahce could see unrest in the stands because of the political tension between Russia and Turkey following the shooting down of a Russian jet by Turkey in November.

While there was no violence in the first leg in Istanbul, which Fenerbahce won 2-0, some Turkish fans were angered when Lokomotiv midfielder Dmitry Tarasov displayed a T-shirt featuring Russian President Vladimir Putin at the end of the game.

Russia's Interior Ministry, which controls the police, has appealed for Lokomotiv fans to remain calm during the game.

"We are counting on you being able to express not only respectful support for the players in their struggle against the opposition, but also to behave in a law-abiding and appropriate manner, and to properly represent a Russian club and your country," the ministry said in an address reported by the Interfax news agency.

STRONG SPAIN

Spanish clubs have a strong record in the Europa League and there's a good chance all four of this season's representatives could make it through to the last 16.

Defending champion Sevilla travels to Molde protecting a 3-0 lead from the first leg, Valencia has a 6-0 lead over Rapid Vienna, Villarreal heads to Italy with a 1-0 lead against Napoli, and Athletic Bilbao is ahead 1-0 against Marseille.

TOTTENHAM'S PRIORITIES

Tottenham is even with Fiorentina heading into the second leg in London after a 1-1 draw, and it's likely some of the English club's fans won't be too upset if their team is knocked out.

Tottenham is a genuine challenger for the English league title for the first time in a generation, and exiting the Europa League would allow the team to focus purely on the domestic championship for the rest of the season.

The path was further cleared over the weekend when Tottenham was eliminated from the FA Cup in the fifth round.

Tottenham manager Mauricio Pochettino rested some key players, like Harry Kane, for the first leg.