Arsenal again heads into a new Premier League season with a promising squad of young players. The difference this year is that fans seem to be wondering if Arsene Wenger is still the man to guide them.

The Gunners were in contention for four trophies but fell apart after losing February's League Cup final to Birmingham, which was eventually relegated. For the first time in his 15 years at the club, many supporters who regularly proclaimed the mantra ''Arsene knows'' began to really question Wenger.

''The last part was the toughest season in my career,'' Wenger said. ''Emotionally, it was very difficult because we were on a low and then you could see the last three or four weeks were very difficult.''

But things could get even tougher this time around. Captain Cesc Fabregas may yet depart for Barcelona and preseason has already exposed the defensive weaknesses about which fans have long complained.

Arsenal slipped to fourth place last season - 12 points behind champion Manchester United - and some supporters are predicting the team could finish outside the top four for the first time since Wenger arrived in 1996.

Despite calls for high-profile, ready-made stars to bolster the squad, Wenger is resolutely sticking to his principles and believes his squad is strong enough to compete for honors.

''I'm very happy with the way we do things and the players we develop and what we try to achieve,'' Wenger said. ''Unfortunately, last year we finished with a bitter taste in our mouth. But we know we were very, very close.

''It's down to how much you want it.''

While many fans are questioning the wisdom of Wenger's approach, others are mindful that Arsenal only won two league titles in 25 years before the Frenchman's arrival in 1996. Even those unhappy at a trophyless streak going back to the 2005 FA Cup are short on names to replace him.

''I know some people had a go at Arsene recently,'' former Arsenal striker Thierry Henry said. ''I don't know when it is going to happen but we all know that one day he is going to have to stop or go.

''But the boss changed the face of the club and, for me, I would keep Arsene for life.''

The return from injury of Thomas Vermaelen should offer some solidity, but Wenger does not appear to have a suitable colleague to pair with the Belgian in central defense. Salvatore Squillaci, Johan Djourou and Laurent Koscielny have all made high-profile mistakes.

Arsenal twice led Tottenham by two goals last season but had to settle for a defeat and draw against its fierce local rival, while it also let slip a 4-0 halftime lead to draw 4-4 with Newcastle.

Wenger has said he expects to make signings soon - with proven Premier League defenders Phil Jagielka, Gary Cahill and Christopher Samba reportedly piquing his interest - but reinforcements have yet to arrive.

Kieran Gibbs should be an adequate replacement at left-back following the departure of Gael Clichy to Manchester City but, further forward in the team, much depends on whether Fabregas stays.

Barcelona failed to bring its former youth player back to Spain last year and has had offers rebuffed since the end of last season, but Wenger has conceded that he could leave if the club's valuation was met.

''It is a bit uncertain and I always said he is torn between two loves,'' Wenger said. ''There is the club where he was educated as a very young boy and the club where he has been educated from 16 onwards and he has been given an opportunity.

''I personally can understand that but we want to be certain of his complete commitment.''

Samir Nasri looks likely to play through the final season of his contract but the loss of Fabregas - or of his total commitment to the team - would leave a huge gap to fill. The World Cup winner has scored 57 goals in 303 appearances for the Gunners and set up countless other chances with his drive and vision.

His departure would likely lead to an increase in responsibility and expectation upon the 20-year-old Aaron Ramsey and 19-year-old Jack Wilshere, while Netherlands striker Robin van Persie is the most likely replacement as captain.

''If it goes your way, I do believe that this could be a really good year for me,'' said Van Persie, who scored 18 goals in the second half of last season.

With Van Persie, Gervinho, Maroune Chamakh and Andrei Arshavin in the squad, Arsenal's riches in attack bear comparison to any of its topflight rivals.

Ivory Coast striker Gervinho has impressed in preseason following his arrival from Lille and could fill a place in the squad vacated by Nicklas Bendtner, who has been linked with a move to Portugal.

Arsenal should be in the top four again this season but the continued strengthening of Manchester City and resurgence of Liverpool mean the Gunners may not find it as easy as usual to get there.