Chelsea have enjoyed a terrific start to life under Maurizio Sarri, the man who replaced Antonio Conte in the summer.

The Blues currently sit third in the Premier League table and, like Liverpool and Manchester City above them, remain unbeaten.

However, in order to finish the season above City and Liverpool, they may need to make at least one game-changing signing when the transfer window re-opens in January.

With this in mind, we thought we’d look back at how successful Chelsea’s winter transfer activity has been in every season since the 2008-09 campaign.

The first thing to note is just how many players Chelsea have signed in January over the past 10 years. A total of 20 players have been signed for the club’s first team - but where are they all now?

2009

Gokhan Tore

Signed from Bayer Leverkusen for £500,000, Turkish winger Gokhan Tore failed to make a competitive appearance for Chelsea and was sold two years later to Hamburg.

The 26-year-old, who had a brief loan spell with West Ham during the 2016-17 campaign, plies his trade for Besiktas and has made 26 appearances for the Turkish national team.

2010

N/A

2011

Fernando Torres

Arguably the best forward in world football at his peak with Liverpool, Fernando Torres struggled badly at Stamford Bridge following his controversial £50 million transfer from Anfield in January 2011.

However, the Spain international - who now plays for Sagan Tosu in Japan - still managed to leave Chelsea with FA Cup, UEFA Europa League and UEFA Champions League winners’ medals.

David Luiz

Initially signed in a £21.3 million deal from Benfica, David Luiz spent three years with the Blues before joining Paris Saint-Germain in 2014.

However, the Brazil international was back at the Bridge two years later, having matured into a much more reliable defender.

2012

Kenneth Omeruo

Despite signing for Chelsea back in January 2012, Kenneth Omeruo is yet to make a single appearance for the Blues.

Remarkably, the Nigeria international is still on Chelsea’s books. Over the past six years he’s been loaned to ADO Den Haag, Middlesbrough, Kasimpasa, Alanyaspor, Kasimpasa - and now finds himself on loan at Spanish side Leganes.

Gary Cahill

He may not be every Chelsea fan’s cup of tea these days, but there’s no denying Gary Cahill has been a fantastic servant for the Blues since his £7 million transfer from Bolton in 2012.

The 32-year-old, who could leave Chelsea when the transfer window re-opens, has won a host of major honours at the Bridge including the Champions League and two Premier Leagues.

Lucas Piazon

Widely regarded as one of South American football’s most talented youngsters, Lucas Piazon became eligible to play for Chelsea in January 2012 after agreeing to join the Blues from Sao Paulo a year earlier.

He has since played for several clubs on loan - including Malaga, Eintracht Frankfurt and, most recently, Fulham - but the 24-year-old should probably now forget about forcing his way into Chelsea’s first team.

Patrick Bamford

Chelsea thought they’d signed a potential superstar when they secured the services of highly-rated Patrick Bamford, 18 at the time, in a £1.5 million deal from Nottingham Forest in January 2012.

Fast-forward almost seven years, though, and Bamford - who now plays for Leeds United - has failed to live up to his early-career hype.

Kevin De Bruyne

It’s still hard to believe how badly Chelsea wasted Kevin De Bruyne following his £6.7 million move from Genk in January 2012.

The Belgian winger - who has established his status as one of the best players in the Premier League and European football at Manchester City - played just nine times(!) for the Blues before being sold to Wolfsburg.

2013

Wallace

Like Lucas Piazon before him, Wallace moved to Chelsea far too early in his career and paid a heavy price for doing so.

The Brazilian full-back’s career stagnated at Stamford Bridge - despite loan spells with the likes of Inter Milan, Vitesse and Gremio - and the 24-year-old currently finds himself without a club.

Demba Ba

With Fernando Torres struggling to score goals, Demba Ba was brought in to ease the burden on the Spanish striker.

However, the Senegalese striker - who had been superb at Newcastle United - struggled to score goals consistently at Stamford Bridge.

Now 33, Ba currently plays for the Chinese team Shanghai Shenhua.

2014

Bertrand Traore

Another player who Chelsea may regret not keeping hold of, Bertrand Traore has been a hit at Lyon since leaving Stamford Bridge permanently in 2017, scoring 18 goals in his debut season at the Parc Olympique Lyonnais.

The Burkina Faso international, 23, scored four goals in 16 games for Chelsea but was never truly given a fair crack of the whip.

Nemanja Matic

Nemanja Matic returned to Chelsea in January 2014 after shining for Portuguese giants Benfica.

The Serbia international went on to become one of the Premier League’s best holding midfielders but was surprisingly sold to Manchester United in 2017 after Antonio Conte secured the services of Tiemoue Bakayoko.

Matic, however, is currently under fire at Old Trafford after a string of disappointing performances for the Red Devils during the opening months of the current campaign.

Mohamed Salah

Like Kevin De Bruyne, it now seems completely baffling that Chelsea allowed Mohamed Salah to leave Stamford Bridge so soon after signing him.

Salah only made 19 appearances for the Blues, scoring two goals, before being sold to AS Roma.

The 26-year-old, who has netted a remarkable 52 goals in 69 games for Liverpool, is now widely regarded as one of the best forwards on the planet.

Kurt Zouma

Signed for £12.5 million from Saint-Etienne, Kurt Zouma’s career has struggled to fulfil his huge potential mainly because of a serious knee injury he suffered in February 2016.

The powerful French defender, who turned 24 last month, is currently trying to rediscover his best form on loan at Everton.

Mario Pasalic

Unfortunately, Mario Pasalic is yet another talented youngster signed by Chelsea but never given a chance to shine.

The Croatian midfielder - who has been capped eight times for his country - has been loaned out to various European clubs including AS Monaco and AC Milan.

The 23-year-old is currently on loan with Atalanta, but it’s hard to imagine he’ll ever be deemed good enough to play for Chelsea.

2015

Juan Cuadrado

Signed for £23 million from Fiorentina, Juan Cuadrado only made 15 appearances for Chelsea before he was sold to Juventus.

Chelsea’s loss, however, has undoubtedly been Juve’s gain. The Colombia international has helped the Old Lady win three successive Serie A titles, as well as three successive Coppa Italia titles.

2016

Matt Miazga

Chelsea fans have seen very little of Matt Miazga following his £3.5 million move from New York Red Bulls in January 2016.

The United States international has made two appearances for the Blues to date but played a lot more with loan club Vitesse during the 2016-17 and 2017-18 campaigns.

Miazga is currently on loan at Nantes.

2017

N/A

2018

Ross Barkley

Eyebrows were raised when Chelsea forked out £15 million for Everton’s inconsistent, injury-plagued midfielder Ross Barkley in January 2018.

However, the 24-year-old has proved a smart buy for the Blues and is improving all the time under current coach Maurizio Sarri.

Emerson

Because Marcos Alonso is Chelsea’s first-choice left-back, we haven’t seen much of Emerson following his £17.5 million move from AS Roma.

Still, the Italy international - who turned 24 in August - has looked pretty decent whenever he’s played.

Olivier Giroud

Although Olivier Giroud has only scored six goals in his first 30 appearances for Chelsea, the former Arsenal man has been an excellent addition to the Blues’ squad.

Eden Hazard described his teammate as “the world’s best targetman” earlier this season, which tells you everything about the impact he’s made at the Bridge.