It might not feel like it but it has actually been over 12 years since Jose Mourinho took charge of his first game in the Premier League.
He was given a tough examination on his managerial debut in English football by being drawn to face Sir Alex Ferguson's Manchester United, the team Mourinho ironically now coaches.
The Portuguese boss' Blues came out impressive 1-0 winners on the opening day of the 2004/05 season and would subsequently storm towards the title just a matter of months later.
But with Mourinho set to return to Stamford Bridge for the first time since getting sacked last December with his Man United team on Sunday, we've decided to have a look at the two teams that played on that August afternoon 12 years ago and examine what they are doing today.
Twelve years is a long time in football so don't be surprised if a couple of names crop up that you don't recognise.
GK: Petr Cech
An injury to Carlo Cudicini meant Cech was given his Chelsea debut in this game. He would go on to establish himself as the No.1 choice before Thibaut Courtois' arrival a few years later forced the ex-Czech Republic international to move to Arsenal in 2015.
RB: Paulo Ferreira
The Portuguese full-back was another to make his bow against the Red Devils and went on to become a firm fan favourite. Ferreira eventually retired at the club in 2013 and was rumoured to have started work on his coaching badges but is yet to secure a role.
CB: William Gallas
After leaving Chelsea in 2006, Gallas controversially stayed in London for spells at Arsenal and Tottenham before eventually finishing off his career in Australia with Perth Glory in 2014.
CB: John Terry
The former England captain is the only player from either team to still be at the same club without retiring, although an injury has meant Terry has now lost his place in Antonio Conte's current starting XI.
LB: Wayne Bridge
Bridge spent six seasons as a Chelsea player before moving to Manchester City in 2009. Various spells at three other clubs then followed and the full-back ended his career at Reading two years ago.
Geremi has disappeared from the media spotlight since he hung up his boots in 2011 at Greek side Athlitiki Enosi Larissa.
CM: Frank Lampard
Most Chelsea fans had hoped Lampard would have ended his career at Stamford Bridge but he fell out of favour in 2014, spent a year at Manchester City and is now enjoying the final part of his playing days in MLS with New York City.
CM: Claude Makelele
Another fan favourite in west London, Makelele retired in 2011 at Paris Saint-Germain, where he subsequently became assistant manager. He then became the head coach at Bastia in 2014 but was sacked after less than six months in charge and hasn't taken up another managerial role since.
LM: Alexey Smertin
Arguably the strangest post-football career award goes to the former Russia captain, who was actually an elected as an MP in the Altai region of his home country in 2009.
CF: Didier Drogba
After his second spell at Stamford Bridge concluded in 2015, Drogba moved to Montreal Impact in MLS where he continues to find the back of the net on a regular basis - despite not always seeing eye-to-eye with his manager.
CF: Eidur Gudjohnsen
The Icelandic forward scored the only goal of the game that day and, like Drogba, Gudjohnsen has no intention of retiring just yet. The 38-year-old has recently signed for Indian Super League side Pune City.
GK: Tim Howard
Howard was arguably at fault for Gudjohnsen's goal and didn't enjoy the best of careers at Old Trafford. After being released by Everton in the summer, the American has returned home to play for the Colorado Rapids.
RB: Gary Neville
As well as part-owning Salford City on top of a couple of hotels and restaurants, Neville is regularly spotted on Sky Sports' coverage of the Premier League. Failed stints in charge of Valencia and coach of England suggest the full-back is better suited to working in the media.
CB: Roy Keane
United had so many injuries Keane was forced to deputise at the back 12 years ago.
He also tried his hand at management but now seems satisfied combining his role as a coach for the Republic of Ireland with his punditry duties for ITV.
CB: Mikel Silvestre
Silvestre made the risky move to Arsenal after leaving Old Trafford in 2008 but finished his career in the inaugural Indian Super League a few years late.
LB: Quinton Fortune
The South African returned to the club in 2012 to complete his coaching badges and spent a brief period coaching Cardiff City's Under-21 side. He has also done a bit of punditry during the 2015 African Cup of Nations.
RM: Liam Miller
Arguably the most obscure name on this list, Miller only made nine Premier League appearances for the Red Devils. The Irish midfielder spent a bit of time with three clubs in Australia and is now competing for Wilmington Hammerheads in the third tier of America's league system.
CM: John O'Shea
At 35, O'Shea is still just about playing in the Premier League with Sunderland but the Black Cats look set for another tough fight against relegation.
CM: Eric Djemba-Djemba
Djemba-Djemba, who is more memorable for his name rather than anything he did for Man United, is currently on loan at amateur side Persipa Padalarang from fellow Indonesian team Persebaya Surabaya.
CM: Paul Scholes
Scholes was coaxed out of retirement briefly in 2012 but hung his boots up for good a year later. He has tried his hand at coaching in the past but is now more commonly seen critiquing the current Man United stars as a pundit for BT.
LM: Ryan Giggs
Giggs finally ended his 26-year association with the club during the summer to pursue his own career in management but has had little luck so far.
ST: Alan Smith
Smith took the surprising decision to drop down two divisions four years ago and after a spell at MK Dons is now playing for Notts County in League Two as a midfielder.