New Chelsea head coach Liam Rosenior arrived with optimism, but Wednesday's 2-1 defeat at Fulham underlined the scale of the task ahead.

The 41-year-old described his appointment as "one of the proudest moments of his life", yet the reality was clear as Chelsea dropped out of the Premier League top five for the first time since August.

Sitting in the directors' box alongside co-owner Behdad Eghbali and members of the sporting leadership team, Rosenior watched as the side he has inherited slipped to eighth.

He replaced Enzo Maresca after the Italian fell out with the Blues hierarchy, with Rosenior joining from French club Strasbourg who share Chelsea's owners.

Those decision-makers were targeted by chants from the away end during the match at Fulham, while the Chelsea players struggled against their west London rivals on the pitch.

Chelsea have won just one of their past nine league games and two of 11 in all competitions, falling from potential title contenders in November to a side now lagging far behind.

They have ground to make up to achieve their minimum aim this season – qualifying for the Champions League, which should be achievable with a top-five finish.

BBC Sport looks at the problems Rosenior faces on and off the pitch.

If Chelsea's relationship with the fans isn't broken, it is certainly fraying.

Just hours after Rosenior was confirmed in his new post, the Chelsea Supporters' Trust released a highly critical survey - not aimed at the appointment, but at the club's leadership.

Among the headlines was that more than half of respondents doubt Chelsea will achieve success in the next three to five years under the current regime. A similar proportion lack confidence in the ownership's decision-making.

Rosenior seemed aware of the stakes. In his first interview with the club's media channels, he used the word 'win' 14 times - a clear signal that he understands the only way to repair this fractured relationship is through results.

The former Fulham defender also referenced playing against Didier Drogba, Arjen Robben, Frank Lampard, Joe Cole and Michael Essien - acknowledging the fear factor Chelsea once commanded during the Roman Abramovich ownership era. These were savvy remarks from the London-born coach, showing he understands the club's identity.

Yet even he may not grasp the depth of anger that exists among the fanbase. On Wednesday, chants in support of the sanctioned Russian oligarch who transformed Chelsea rang out across Stamford Bridge, alongside unsavoury songs aimed at co-controlling owner Eghbali and Clearlake Capital.

There will also be a protest before Rosenior's first league match against Brentford, who leapfrogged them in the table on Wednesday, on Saturday week.

Rosenior must know he could become a target himself if results do not come quickly. He embodies everything Todd Boehly and Clearlake believe in: he is young, progressive, and connected to their multi-club model via Strasbourg.

Signing off his first interview, Rosenior said: "Believe in what is an amazing football club, believe in the players, and when you give energy to the team, you help them win. That's why we are here. I can't wait to meet them and do that soon."

Chelsea have spent more than £1.5bn on new players since 2022. Although they have raised over £750m through player sales, results have not matched the scale of investment.

Much of the criticism has focused on the club assembling the youngest squad in the Premier League, with an average starting XI aged under 24. No team that young has ever won the title in the Premier League era.

Chelsea have shown flashes of quality but often lose control and drop points. Former boss Maresca highlighted the issue after his side dropped a league-high 15 points from winning positions this season.

Rosenior faces similar concerns. His Strasbourg team, with an average age of around 21, dropped 13 points from winning positions and won only two of their past 10 Ligue 1 matches.

Insiders at Chelsea insist they want to be Champions League regulars and eventually challenge for the biggest titles. Yet to achieve even their minimum aims, Chelsea and Rosenior need to find momentum quickly.

Chelsea were reduced to 10 men at Fulham when Marc Cucurella was sent off for pulling back Harry Wilson as he broke through on goal.

Wilson later scored the winner with a fine finish in the 82nd minute.

Caretaker manager Calum McFarlane defended Cucurella by saying: "There's been a lot made of the red cards this season. I don't think this one is ill-disciplined. This is football. You get caught one-v-one and Marc is one of the best defenders in the world."

However, McFarlane admitted concern over three yellow cards that followed immediately for dissent after the dismissal, shown to Cole Palmer, Enzo Fernandez and Tosin Adarabioyo.

"The three yellow cards directly after is something we'll have to look at, but I would argue that we don't want that to happen," McFarlane said.

McFarlane was also later cautioned for questioning the referee.

Since the start of the 2023-24 season, Chelsea have received 251 yellow cards and 11 reds – the most of any Premier League club. They have had five red cards for players in the league this season, and one more in their remaining 17 matches would equal an unwanted club record that was set in 2007-08.

Former boss Maresca had been trying to address the issue before his departure.

Rosenior joined team meetings before the Fulham match and travelled with the squad to Craven Cottage.

His first full training session is scheduled for Thursday. He will then be presented to the media on Friday before selecting his first team for Saturday's FA Cup third-round game at Charlton Athletic.

In the following week, Chelsea face Arsenal in the Carabao Cup semi-final, followed by Rosenior's first Premier League match at home to Brentford.