Chelsea have not won the Premier League since Antonio Conte led them to the 2016-17 title - and facing the Italian's Napoli side on Wednesday brings that into sharp focus.

Conte's triumph came in the season when Pep Guardiola began his reign as Manchester City boss. It was Conte's first campaign in England, too, and Chelsea enjoyed a club-record 13 consecutive league wins on their way to lifting the championship with 93 points. Their fifth Premier League crown in 13 seasons matched Manchester United's achievement in that same period. Chelsea - or indeed United - haven't ruled the roost since, amid an extensive turnover of players and coaches.

Nine years down the line, we reach a dramatic finale to the Champions League's opening phase. Liam Rosenior's Chelsea need a win against Conte's Napoli at the Stadio Diego Armando Maradona to go directly into the last-16 stage. Their hosts - Serie A champions last season - must win to stay in the competition. Like so many aspects of Chelsea's recent history, you'd struggle to write this script.

Aside from Thomas Tuchel's Champions League triumph in 2021, the heights of Conte's short stint at the wheel have not been matched at Chelsea. Rosenior, 41, is the latest of seven head coaches, not including interim appointments, to have led Chelsea since Conte was sacked in July 2018.

Speaking about Conte on Tuesday in Naples, Rosenior said: "I have huge respect for him. Firstly, as a player, he was a magnificent footballer. He then went on to - and still has - an incredible career as a coach. I think his passion as a player transmits to the passion in his teams and obviously when I was younger watching Chelsea play in the manner that they did, defensively so strong. [Eden] Hazard was incredible in those moments, and he [Conte] has gone on to prove what an amazing manager he is and he's won many titles, including an incredible title here last year."

After winning the Premier League, Conte fell out with the Chelsea hierarchy under then-owner Roman Abramovich - a rift that sparked his season-long downfall. Chelsea missed out on several key transfer targets as Romelu Lukaku went to Manchester United, Virgil van Dijk to Liverpool and Kyle Walker to Manchester City. Instead, they signed Tiemoue Bakayoko, Alvaro Morata, Davide Zappacosta and Danny Drinkwater, with only Antonio Rudiger proving a success among the club's five major additions.

Conte's second season marked the beginning of Chelsea's transition into what many have described as a 'cup team', as they lifted the FA Cup. In the Premier League, they finished fifth, 30 points behind Guardiola's 100-point Manchester City, and missed out on Champions League qualification.

Even when Chelsea won the title in 2017, Conte described his success as a "miracle" because it involved the "same players that the season before finished 10th." Despite having had an ill-fated spell at rivals Tottenham since his Stamford Bridge reign, Conte will be remembered fondly by Chelsea supporters and took a positive tone when recalling his two years at Stamford Bridge. "It was a great experience," Conte said on the eve of the reunion with his former club. "We're talking about a fantastic club with a great vision, a winning mentality and the same desire to win."

Napoli also boast three former Chelsea players in Romelu Lukaku, Kevin de Bruyne and Billy Gilmour, but all three are injured and expected to miss Wednesday's match.

Napoli have faced Chelsea before - in a dramatic Champions League last‑16 tie in 2012. Chelsea lost the first leg 3–1 in Naples before producing a 4–1 comeback win at Stamford Bridge on their way to lifting the trophy for the first time under Roberto di Matteo, a mid-season managerial appointment much like current boss Rosenior.

This winter, the breakdown in relations between Enzo Maresca and Chelsea's sporting directors and ownership felt eerily similar to the circumstances surrounding Conte's departure. Ultimately, Maresca's position became untenable and he did not make it to the end of the season, with Rosenior replacing him. In his first campaign, Maresca reduced the gap to the league leaders to 16 points, although Liverpool's total of 84 was the lowest title-winning tally since 2016.

However, instability has been Chelsea's enduring problem when compared with standard-setting clubs such as Manchester City, Liverpool and Arsenal, who have dominated the Premier League in recent years. All three have enjoyed continuity in the dugout and boardroom, a foundation that has helped to underpin sustained success.

Chelsea had hoped to build for the long term around Tuchel, who had close working relationships with director Marina Granovskaia and technical adviser Petr Cech, but UK government sanctions led to the end of the Abramovich-era leadership. When Todd Boehly and Clearlake Capital completed their BlueCo takeover in 2022, they emphasized their ambition to win the Premier League. But relations soon soured with Tuchel, who appeared increasingly strained under the new ownership.

Graham Potter was then appointed, with the intention of replicating the team-building models of Liverpool under Jurgen Klopp and Arsenal under Mikel Arteta, while drawing inspiration from Brighton's recruitment strategy. Yet Chelsea recruited too many players during the first season under new ownership, which created a chaotic dressing room environment that Potter could not manage.

The club subsequently opted for a higher-profile manager, appointing Mauricio Pochettino in 2024, but he did not align with their vision and was followed by the younger Maresca. There remains widespread appreciation for Maresca's work despite his acrimonious departure over a difference in vision with the ownership. His successor, Rosenior, was promoted from within the BlueCo structure - having been head coach at partner club Strasbourg - in an effort to minimise mid-season disruption, work within a structure that is built to focus on developing young players, and maintain a similar style of play to his predecessor.

Conte can look at Chelsea from a distance now, fascinated by how the approach has changed. He said: "Every coach wants to sign young players, but if young players are over £100m like [Moises] Caicedo and [Enzo] Fernandez, it's not for all clubs, especially in Italy. They are doing very well and are doing something important for the future."

The club he led to glory nine seasons ago sit fifth in the Premier League and are 13 points behind leaders Arsenal with 15 matches remaining. Manchester City - still led by Guardiola - are in the hunt. Chelsea have not been considered part of this season's title race since December.

The latest Deloitte Football Money League table placed Chelsea 10th of all European clubs, behind all five of their fellow 'big six' Premier League rivals. Chelsea had been above Tottenham since 2024, but revenues of £506.85m now put them behind those clubs, with Aston Villa also closing the gap. That financial picture can in part be attributed to Tottenham having a new 60,000-seat stadium, which has significantly boosted their matchday and commercial income.

Chelsea have also needed to play catch‑up with clubs such as Manchester City and Manchester United in securing major sponsorship deals, having fallen behind during the later Abramovich years - and they remain without a front-of-shirt sponsor. Chelsea's hectic transfer activity, both incoming and outgoing, has added further complexity. More than £1.5bn has been spent on signings since the 2022 takeover, while over £750m has been raised through player sales. That approach has been driven partly by the desire to rebuild the squad, but also by the need to manage lower revenues that limit spending power under financial regulations through constant player trading.

Rosenior's goals are concentrated on what he can influence. "The aim for us long term and in the short term as well is to compete for trophies," he said. "Whether [nine years without a Premier League title] is too long or not, that comes down to the team, the coaching and the infrastructure of the club."