<notforsyndication>Watch Manchester United v Porto live on RTÉ Two and RTÉ.ie from 7pm on Tuesday. Bill O'Herlihy anchors live coverage of the first leg of the quarter-final from Old Trafford (KO 7.45pm). The programme will also include extended highlights of Villareal v Arsenal. RTÉ.ie streaming is Island of Ireland only. </notforsyndication>

Arsene Wenger is in no doubt his young Arsenal side can come through another test of character and produce the result required against Villarreal at the intimidating El Madrigal tonight.

The Gunners head into the Champions League quarter-final first leg on the back of an improved run of form which has seen them climb back up into the top four of the Barclays Premier League and secure an FA Cup semi-final date with Chelsea at Wembley.

Although leading scorer Robin van Persie did not make the trip to Spain because of a groin problem suffered while on international duty, captain Cesc Fabregas and Togo striker Emmanuel Adebayor will both continue their comebacks against the Yellow Submarine.

There is now a much more positive outlook for the Gunners, following what had been a difficult opening to the campaign.

'The team has become stronger since the beginning of the season,' Wenger said.

'This team has shown a fantastic spirit, because they had to fight against every negative opinion existing in England, and they did that very well.

'I have a lot of respect for my team because of the mental strength they have shown. It is a very young team and my hope is that we can keep them together and develop very well.'

The Arsenal boss added: 'What is important is how much belief we take into the game against Villarreal.

'I am convinced we have enough experience to know that these kind of games are for 180 minutes - and that every single minute is important.'

Arsenal are set to come up against one of their finest former players tonight in Robert Pires. The 35-year-old winger spent six successful seasons at Highbury.

However, the Frenchman's Arsenal career ended on a disappointing note with a last appearance for the Gunners in the 2006 Champions League final defeat to Barcelona, when he was substituted in an early tactical change following the sending off of goalkeeper Jens Lehmann.

Wenger declared: 'Pires was one of the great players I have signed. Of course I would think that opinion would be shared by many Arsenal fans.

'Robert is still loved by the club and have a lot of respect for what he has done for the club.'

Arsenal goalkeeper Manuel Almunia, meanwhile, insists now is the time for Wenger's young Gunners to deliver on the big stage.

'This season looks to be our season,' the Spaniard declared. 'It looks to be the season for the young players to be man enough to face all the big competitions we have.

'Players like Alex Song, Abou Diaby and Theo Walcott - when these players are 100% fit, they can be mentally prepared to be totally professional, and they have the potential to win trophies.

'We can win every single game and we are here to do it.'

Russian midfielder Andrey Arshavin is ineligible for the Champions League having played for Zenit St Petersburg during the group stages before his January transfer to the Emirates Stadium, but France winger Samir Nasri has travelled after overcoming a virus.

Head-to-head
> Villarreal and Arsenal have only met each other during the semi-finals of the 2005/2006 Champions League campaign.
> The Gunners won the first match at home (1-0), through a goal from Kolo Touré on 19 April 2006. A week later the return in Spain resulted in a goalless draw.
> That season was the most successful for both clubs in the Champions League. Arsenal eventually lost the final against FC Barcelona (2-1) on 17 May 2006.
> In five home matches, Villarreal are unbeaten against opponents from England (2-3-0).
> However, Arsenal have lost six of their 10 matches in Spain against Spanish opponents (2-2-6). Arsenal’s last defeat in Spain was against Sevilla FC in a Champions League group match on 27 November 2007.

Villarreal CF
> Villarreal have never lost a home match in the CL (4-6-0).
> Villarreal are unbeaten in their last 15 European home matches, which is a club record.
> The Yellow Submarines have drawn their last two home matches. If they do not beat Arsenal, the club will set a new record for most consecutive winless home matches in the Champions League.
> Arsenal and Villarreal both finished second in their group of this season’s CL. Both clubs are also ranked fourth in their league table. That would mean that both clubs will play in the play-off round in next year’s CL.
> Villarreal substitutes have scored the most goals (6) of all CL teams.
> Club top scorer Joseba Llorente has scored all of his four goals as a substitute. That is the most of all players in this season’s CL campaign. Last season, Dutchman Ryan Babel scored a record five goals as a substitute for Liverpool.
> Pascal Cygan and Robert Pires played for Arsenal before they joined Villarreal in 2006. Pires played 63 CL matches for the Gunners, scoring 11 goals. Cygan played 20 CL matches for Arsenal, without finding the net once.
> Pires played in both matches against Villarreal in the semi-finals of the 2005/2006 CL.
> Ariel Ibagaza, Marcos Senna, Ángel and Guillermo Franco will be suspended if booked.
> Villarreal suffered a 3-0 defeat at the hands of UD Almería in the Spanish league on Saturday.
> Robert Pires was sent off in the 60th minute following his second yellow card of the match.

Arsenal
> Denílson is the only player that has played every minute for Arsenal during this season’s Champions League.
> Robin van Persie and Emmanuel Adebayor are the club's top scorers with three goals.
> Van Persie has scored a total of nine goals in 30 matches for Arsenal in the Champions League. If he scores his 10th goal on Tuesday, he will be the second fastest Gunner to score at least 10 goals in the Champions League for Arsenal, behind Thierry Henry, who needed 23 matches.
> Arsenal have always won in the CL when Van Persie scores.
> The Gunners have used 24 players already in this season’s Champions League. Only Juventus and Real Madrid (both 25) have used more players.
> Abou Diaby and Robin van Persie will be suspended if booked.
> Emmanuel Adebayor made a triumphant return from injury on Saturday 4 April, scoring twice to help Arsenal defeat Manchester City 2-0 in the Premier League.
> The result leaves Arsenal in fourth place in the English top flight, with 58 points from 31 matches.