The Celta Vigo team which beat Liverpool 3-1 in the old Uefa Cup at Estadio Balaidos in 1998

Celta Vigo v Manchester United Venue: Estadio Balaidos Date: Thursday, 4 May Kick-off: 20:05 BST Coverage: Full match commentary on BBC Radio 5 live, listen online and BBC Sport app, live text and report on BBC Sport website

The Europa League is the only major trophy missing from Manchester United's trophy cabinet and they have moved smoothly into the last four under the guidance of Jose Mourinho.

Standing between them and a place in the final in Stockholm on 24 May are Spanish opposition - but not perhaps who you would expect.

Sevilla have won the last three Europa Leagues, but played no part this season after reaching the last 16 of the Champions League.

Spanish sides have won the Europa League - and predecessor Uefa Cup - on 10 occasions, but United's opponents Celta Vigo have never before reached the last four.

Vigo have knocked out Aston Villa and Liverpool in the past - will they conquer United next?

Who are Celta Vigo?

Based in the small city of Vigo (population 200,000) in the wet and windy region of Galicia in the north-west of Spain, close to the Portuguese border, Celta are by no means one of the traditional powerhouses of Spanish football.

The club spent much of its existence bouncing between Spain's top two divisions before an outbreak of success in the late 1990s and early 2000s, when players such as Alexander Mostovoi, Valery Karpin and future Chelsea star Claude Makelele inspired a strong few seasons including a fourth-placed finish in La Liga in 2003.

But Celta then suffered dire financial problems, coming very close to entering administration, and spent five years in the Segunda Division before returning to the top flight in 2012.

They have never won a major trophy but have been getting closer in recent years, reaching the Copa del Rey semi-final in each of the last two seasons and now also progressing to their first European semi-final.

The meeting with United has understandably sparked great excitement among fans, with all tickets for the home leg selling out last week.

Midfielder Claude Makelele (right) spent two seasons at Celta Vigo before playing for Real Madrid, Chelsea and Paris St-Germain

But the tie comes against the dark backdrop of a row with the local council over the ownership of their Balaidos stadium, with club president Carlos Mourino threatening to move to another town.

Controversial but highly rated manager

Celta manager Eduardo Berizzo might not find the red carpet rolled out by United's recently unveiled partners, the lesbian, gay, bisexual, and transgender charity Stonewall, after he once made headlines with homophobic comments about his time as a player in France at Marseille.

In purely footballing terms, though, Berizzo has done an excellent job at Celta since taking over from Barcelona-bound Luis Enrique in the summer of 2014, leading the team to eighth- and sixth-place finishes and instilling an open, entertaining style of play.

His team sit 11th in La Liga with a 4-3 home win over Barcelona back in October one of the highlights of the season.

The 47-year-old Argentine spent the latter stages of his playing days with Celta, and later started his managerial career as coaching guru Marcelo Bielsa's assistant with the Chilean national team before going solo to win a Chilean league title with O'Higgins in 2013.

Eduardo Berizzo has been manager of Celta Vigo since 2014

He generally employs a 4-2-3-1 formation and - like all Bielsa protegees - prefers a fast-paced game with emphasis upon retaining possession (this season Celta rank sixth in La Liga with an average of 52.2% possession per game), and pressing the opposition high up the pitch.

Berizzo's achievements with Celta have seen him linked with bigger clubs, and the fact he is out of contract in the summer has sparked rumours of a possible move to Athletic Bilbao, Sevilla or Valencia, who are all likely to have vacancies at the end of the season.

Ex-Premier League forward line

Celta's strike force is led by two men who previously played for United's fiercest local rivals: ex-Liverpool man Iago Aspas, 29, and 25-year-old Swedish powerhouse John Guidetti, who started his professional career at Manchester City.

Aspas struggled at Anfield, failing to score in any of his 14 Premier League outings for the Reds, and also underperformed in a subsequent loan spell at Sevilla, but he has been reinvigorated since returning to Celta for a second spell with his hometown club.

The relentlessly hard-working forward is very much his boyhood team's symbolic leader, and his 17 league goals so far this season make him the highest-scoring Spaniard in La Liga - he also has netted five in Celta's Europa League campaign.

Iago Aspas is the highest-scoring Spaniard in La Liga this season

That form has earned Aspas call-ups into the Spain squad, and his first goal at international level came with an excellent strike into the top corner in last year's friendly draw against England at Wembley.

Despite his ill-fated Liverpool days, United fans should be wary whenever the ball comes onto his left foot within shooting range.

Guidetti was once tipped as a major star (especially by himself … he is not lacking in self-confidence) but has endured a rather nomadic career to date, joining City at the age of 16 before being sent to five different clubs on loan, including Burnley, Stoke and Celtic.

He has done reasonably well since joining Celta on a free transfer two years ago, and his blend of physical power, technical ability and a cocky demeanour has long encouraged many Swedish fans to regard him as the natural heir to Zlatan Ibrahimovic as the focal point of the national team's forward line.

However, there are also plenty who are gradually losing faith with Guidetti, wondering whether he will ever consistently fulfil his undoubted potential. A European semi-final against Manchester United would be a good place to prove he can.

Midfield talent

Celta are also blessed with a lot of talent in midfield, with the ammunition for Aspas and Guidetti coming from a trio of highly regarded performers who are candidates to earn moves to bigger clubs before too long.

United fans with good memories will already be familiar with Danish international winger Pione Sisto, who scored for his previous club Midtjylland in their first-leg victory over United in last season's Europa League. He also netted the opener in the return leg at Old Trafford, but United bounced back to win 5-1 and go through 6-3 on aggregate.

The talented 22 year-old has not always been a regular starter for Celta this season, but he played a major part in their Europa League campaign by scoring in both legs of the quarter-final victory over Genk, including a screamer in the second leg to secure their progression.

Another threat from wide positions is provided by 21-year-old Belgian Theo Bongonda, whose ability to beat defenders with ease is often let down by an erratic final ball. Although he is not consistent, Bongonda is a major threat, especially on the break.

The scoreboard at Celta Vigo after beating Spanish champions Barcelona in October

Celta's key player in terms of knitting together the midfield and attack is another Dane, Daniel Wass, a versatile performer who occasionally operates wide but now more often plays 'in the hole' behind the frontman, creating spaces in the opposition defence with his excellent technique and ability to read the game.

And watch out for the two full-backs, Jonny Castro and Hugo Mallo, who are both good on the ball and more than capable of getting forward to support their wingers in attack.

Celta Vigo's Europa League charge

15 September: Standard Liege (away) group stage D 1-1 16 February: Shakhtar Donetsk (home) last-32 L 0-1 29 September: Panathinaikos (home) group stage W 2-0 23 February: Shakhtar Donetsk (away) last-32 W 2-0 (aet) 20 October: Ajax (home) group stage D 2-2 9 March: Krasnodar (home) last-16 W 2-1 3 November: Ajax (away) group stage L 2-3 16 March: Krasnodar (away) last-16 W 2-0 24 November: Standard Liege (home) group stage D 1-1 13 April: Genk (home) quarter-finals W 3-2 8 December: Panathinaikos (away) group stage W 2-0 20 April: Genk (away) quarter-finals D 1-1

Big game pedigree

There is little danger that Celta will be overawed by facing the might of Manchester United, because they boast a decent record against Spain's biggest clubs in the last few years.

For starters, the Galicians are the only team to have beaten Barcelona three times during Luis Enrique's time in charge at the Nou Camp, including 4-1 and 4-3 home wins in the last two league campaigns.

Celta also knocked Real Madrid out of this season's Copa del Rey, following up a 2-1 first leg victory at the Bernabeu with a frantic and nervy 2-2 draw in the return meeting.

Celta Vigo fans outside Estadio Balaidos lit flares to greet the coach carrying their team before the Copa del Rey aggregate win over Real Madrid in January

And they conquered Atletico Madrid in last season's cup, again over two legs, notably becoming only the second visiting team to score three goals in a cup tie at Atletico's Vicente Calderon stadium during Diego Simeone's five years in charge (the first was Barcelona).

So, big-name opposition are no cause of fear for Celta, who will certainly not head into their encounter with United sharing the bookmakers' view that they are major underdogs.