Arsenal boss Wenger promises new signing after win in Europe

But after being outplayed, particularly in the opening period, Arsenal boss Wenger knows he needs to strengthen his squad, with a central midfielder top of his list.

'Something will certainly be done ahead of the second leg on 27 August, but not before Saturday,' said Wenger as his side took a massive step towards the £20million bonus for being among Europe's elite.

Strike one: William Gallas bundles in the first goal for Arsenal last night.

With his squad hit by injuries, Wenger admits it is unlikely he will be able to make many changes for Saturday's Premier League game against West Brom. Wenger, who had to leave Cesc Fabregas, Philippe Senderos, Samir Nasri and Kolo Toure in London, said: 'Our squad looks big because the players who were here did well.

'If you look at the number of players we had out you could say it was very positive for us.

'The game on Saturday morning comes very quickly, but in fairness I am not in a position where I can make many changes at the moment.

'We could have Nasri back and maybe Toure (left).'

Captain Gallas, who repaid some of Wenger's faith in giving him back the armband after a difficult first season in charge of the side, insists that Arsenal's youngsters are good enough to challenge on all fronts.

'They have got the control and they have got the quality and if they play for Arsenal then that means they are very good,' said Gallas.

'I am happy for them because when I was the same age as them I don't think I was at a big club like Arsenal. It is a joy to work with them everyday.'

However, Gallas' former Chelsea boss, Jose Mourinho, thinks the lack of older players in the Arsenal squad will prevent them winning the title.

'I would put Chelsea, Manchester United and Liverpool as favourites again to win the Premier League. Arsenal also have a great team, but I'm not sure if the group have enough experience and quality to win,' said the Inter Milan manager.

'I see nobody else to win the Premier League, but Tottenham surely have the quality to fight for a top-four finish.

'I cannot say who the surprise team will be, but we always wait for a better Newcastle. They are a top club, they have huge support and they have good players, so we wait for more from them.'