A problem of plenty: Chelsea must find the right defensive combination

A large part of Chelsea's stellar campaign in their first season under Antonio Conte was attributed to their rock-solid defence. Over the course of 38 Premier League games, Chelsea mustered 16 clean sheets, earning goalkeeper Thibaut Courtois the Golden Glove. The switch to a back-three, six games into a mediocre start to the campaign, proved to be a catalyst for a 13-match winning streak which equalled the record held at that time by Arsenal (the record was recently surpassed by Guardiola's Man City).

Antonio Conte stuck to a defence of Azpilicueta-Luiz-Cahill for most of the games, and this provided a stability and chemistry which made Chelsea one of the best defensive sides in 16/17.

The title-win also marked the end of an era, as John Terry, Chelsea's captain and arguably the best defender of the last decade in English football, brought down the curtain on his illustrious career with the Blues. Elsewhere, a young Chelsea loanee Andreas Christensen was quickly making a name for himself, winning Danish Talent of the year in 2015 and being voted Player of the Season for Borussia Mönchengladbach. Kurt Zouma too was eager for first team action after recovering from an injury that shadowed his impressive debut season with Chelsea. Also in contention for a spot was Nathan Ake, a Chelsea homegrown player who was called back from his loan at Bournemouth in January.

Despite the stellar defensive displays throughout the season and the young guns making a case for themselves, it was perhaps perplexing to the fans that Chelsea seemed to make defensive reinforcements their first priority in the summer of 2017. Various rumours emerged, with players like Alex Sandro, Leonardo Bonucci, and Virgil van Dijk being linked with a move to Stamford Bridge. However, none of the links materialised, and Chelsea ultimately brought in Antonio Rudiger and David Zappacosta as additions.

Andreas Christensen too joined the squad and was promised game-time to help with his development. Zouma was loaned to Stoke City, and Ake was sold to Bournemouth for £20m which once again brought the focus onto Chelsea's policy of not using youth to the best of their abilities.

Antonio Rudiger signed for Chelsea at a reported fee of £34m

The 2017/18 season began on a shocking note for the defending champions, as Chelsea lost 3-2 at home to Burnley, with Gary Cahill and Cesc Fabregas receiving red cards. The loss of their captain, however, didn't deter Chelsea, as Rudiger stood in for him in their 2-1 win over Tottenham one week later. The young German performed well, and has since featured regularly in the squad, with 13 Premier League appearances to his name. This has meant lesser game time for Cahill, who has also made 13 Premier League appearances in 19 games this season (compared to 37 in 38 last season).

Meanwhile, David Luiz picked up a knee injury and reportedly had a bust-up with Conte, and thus has been sidelined for much of the season. Rumours suggest that Luiz may be on his way out in January, with Barcelona and AC Milan showing interest, although Conte and Chelsea have refuted these claims. This, however, created the perfect opportunity for young Christensen, who has earned the adulation of the fans with his maturity and composure.

The young Dane has made 15 league appearances, nearly twice as many as Luiz who has only 8 league appearances to his name. Regular game time was one of Christensen's demands, and the sidelining of Luiz has helped.

Andreas Christensen has displayed great maturity in taking on some of PL's best strikers

As the January transfer window approaches, rumours are doing rounds once again linking Chelsea to Sandro, who is supposedly discontent at Juventus and is looking for a move. Reports suggest Juve have dropped their asking price to £50m, which is what Chelsea offered in the summer and thus money shouldn't be a problem in prying the Brazilian left-back away from Turin.

Former Juventus centre-back Bonucci who made a shocking move to rival club AC Milan in the summer is also reportedly unhappy and looking for a move, and several clubs including Chelsea are interested. However, the Blues' policy of handing out only one-year contracts to players aged over 30 may discourage the 30-year-old Bonucci from making the move.

Antonio Conte thus faces an unfamiliar problem with Chelsea's defence: a problem of plenty. With Azpilicueta, Cahill, Luiz, Rudiger, Christensen all seeking regular game time, and youngsters like Kurt Zouma and Ethan Ampadu who are eager to break into the first team, a big money move for Bonucci or van Dijk will further crowd a position which only three can occupy.

A shift to a back four will require a major tactical change, which Conte may not be willing to do given the success of his 3-4-3 formation. The Italian manager is also known to be stubborn with tactics, although the recent shift to a 3-5-2 shows that he can be flexible when needed.

The 17-year-old Ampadu is also quickly rising through the ranks, having made history by becoming Chelsea's first millennial player

Antonio Conte and the Chelsea board must thus find the right solution for their defence which has been fairly inconsistent this season, perhaps producing their worst display in the 3-0 loss to Roma. Chelsea have had recent problems with youngsters like Kevin De Bruyne, Romelu Lukaku and Mohamed Salah leaving due to lack of opportunities only to be world class players for their rivals, and they'd want to avoid the same regret with players like Christensen and Ampadu.

At the same time, Azpilicueta and Luiz are aged 28, and 30 respectively, meaning they are in their peak years. Benching the senior players may also cause unrest in the locker room, a situation which has managers being sacked from Chelsea. The Blues don't have the luxury of teams like Real Madrid, where players are content with being on the bench.

With the World Cup coming up, players will be looking for regular game time to ensure their position in the national team.To find the right balance between stability and rotation, and between youth and experience, is a real challenge for Chelsea and they must find the solution soon and approach the January transfer window accordingly.