Arsene Wenger believes Arsenal urgently need to show more authority in defensive situations if they are to avoid what now threatens to become another barren season.

The Arsenal coach is clearly worried by the inconsistencies undermining a team that, in the space of a month, has slipped from top to third in the Premier League, six points behind leaders Manchester United.

After the 2-1 defeat at Chelsea last weekend, another setback at Bolton tomorrow will almost certainly end any faint hopes they have of recapturing the title. Arsenal, remember, have lost their last three Premier League games at the Reebok Stadium.

With the first leg of their Champions League quarter-final against Liverpool less than a week away, Didier Drogba's double strike at Stamford Bridge raised questions about Arsenal's back four and prompted Wenger to observe: "We have some defensive problems that need to be sorted out."

What problems? Wenger has every right to be proud of Arsenal's enduring defensive stability; a reputation that can be traced to George Graham's back four of Lee Dixon, Tony Adams, Steve Bould and Nigel Winterburn.

At different times Graham also had David O'Leary and Martin Keown to call upon and this ensured he invariably had the strongest centre-back partnership in the top division during his eight years in charge.

"Every Arsenal defence since then has been compared to what we had and I think that's a bit unfair," said former left-back Winterburn, who played 600 games in 12 years at the club. "Arsenal play a different game these days. They take far more risks than we did and that includes the defensive players.

"When I was playing I'd lash the ball away if I got in trouble and happily concede a throw-in but this team are reluctant to do that. They want to play their way out of trouble and you have to admire them for that. They always want to create attacking opportunities.

"When [Gael] Clichy moves forward, for instance, I often notice [Bacary] Sagna, on the other side, in advance of his two centrebacks. When I was playing, if I attacked up one wing Lee Dixon had to hold back and, if he attacked, I held back."

At Stamford Bridge, though, attacking from defensive positions was not the problem - right-back Sagna actually headed the opening goal.

The underlying issue for Arsenal was an inability to hold their lead with 30 minutes remaining.

"I think they get a bit bullied at times," said Winterburn. "We saw that on Sunday when Drogba hustled them. As good as [William] Gallas and [Kolo] Toure are as footballers, neither is 6ft 5in. When Bould and Adams were together in the heart of our defence, no one bullied us.

"And it's not always about just being good in the air and winning the first ball. It's good to have players around the man attacking the ball so there's always someone to pick up the bits and pieces. That requires good communications between your defenders.

"When I was playing, the back four would often dictate the pattern of play. If we felt under a bit of pressure we'd get the midfield to provide a shield. We'd get Patrick Vieira and Manu Petit to sit tight in the middle for 15 minutes and block everything off. It made it really difficult for the opposition but it's not the sort of thing the modern Arsenal do."

Other issues have also contributed to Arsenal's decline. The loss of Eduardo with a broken leg was a huge blow and has coincided with a serious dip in the goalscoring form of Emmanuel Adebayor. He has not scored a Premier League goal since Arsenal's last win - against Blackburn on 11 February - and, incidentally, since he cut off his dreadlocks.

The loss of Eduardo forced Wenger to hurry back Robin van Persie, probably sooner than he would have liked. Tomas Rosicky's protracted knee problem has also been significant. He and Alexander Hleb together gave Arsenal unrivalled attacking options across the width of the pitch.

Arsenal have taken only four points from five Premier League games since Manchester United knocked them out of the FA Cup with a 4-0 win at Old Trafford. But during that run they have secured an epic 2-0 Champions League win over AC Milan in Italy, so it's not all doom and gloom.

But their domestic inconsistency has produced signs of frustration - that petulant sulk from captain Gallas at Birmingham for instance - and has exposed Toure's tired form since the African Nations' Cup.

"In my opinion they've had a terrific season," said Winterburn. "Yes, it's gone wrong in the Premier League but they could still have a big say.

"The impetus is now with United, so Arsenal will have to go to Old Trafford and win to have any chance.

The thing is that this team are capable of doing just that."