Chelsea have started the search for their new manager with Antonio Conte increasingly likely to leave Stamford Bridge at the end of the season.
The Italian is preparing to move on a year before the expiry of his contract, with the Blues already looking at the contenders to replace him.
Among the frontrunners are the Juventus coach Max Allegri, former Barcelona boss Luis Enrique, Napoli manager Maurizio Sarri and Atletico Madrid's Diego Simeone.
We compare the careers and achievements of the four bosses in the frame for the Stamford Bridge hotseat.
Age: 50 Nationality: Italian Current club: Juventus (contracted until 2020)
Previous clubs: Aglianese, Real SPAL, Grosseto, Sassuolo, Cagliari, Milan
Allegri was the man who succeeded Conte at Juventus and he has successfully managed to maintain their standards domestically as well as lead them to two Champions League finals.
Though contracted to Juventus until 2020, having extended his deal just last year, Allegri does have ambitions to test himself outside of Italy for the first time.
Having bossed two of the Serie A giants in Juve and Milan, Allegri certainly knows what it is like to manage under the pressure of sky-high expectations and still thrive.
He also favours an exciting, attacking brand of football and gets winning results, which would certainly win the favour of Chelsea owner Roman Abramovich.
Given that Allegri has taken Juve forward on the European stage, the club's hierarchy will be reluctant to lose him, but the man himself may find the lure of a new challenge in England irresistible.
Trophy cabinet: (Milan) Serie A 2010-11, Italian Super Cup 2011; (Juventus) Serie A 2014-15, 2015-16, 2016-17, Italian Cup 2014-15, 2015-16, 2016-17; Italian Super Cup 2015; Champions League runner-up 2014-15, 2016-17
Age: 47 Nationality: Spanish Current club: None
Previous clubs: Barcelona B, Roma, Celta Vigo, Barcelona
Currently without a club following his departure from Barcelona upon the expiry of his three-year deal last summer.
Luis Enrique has been waiting for another opportunity to come up ever since and has, in the past, expressed an interest in managing in England.
He maintained Barcelona's golden period of success during his three seasons at the helm, winning two league titles, three Spanish Cups and the Champions League when they defeated Juventus 3-1 in 2015.
This impressive CV, his relative youth, and the attractive brand of football he championed at the Nou Camp will all be appealing to Chelsea.
Trophy cabinet: (Barcelona) La Liga 2014-15, 2015-16; Spanish Cup 2014-15, 2015-16, 2016-17; Spanish Super Cup 2016; Champions League 2014-15; UEFA Super Cup 2015; FIFA Club World Cup 2015
Age: 59 Nationality: Italian Current club: Napoli (contracted until 2020)
Previous clubs: Stia, Faellese, Cavriglia, Antella, Valdema, Tegoleto, Sansovino, Sangiovannese, Pescara, Arezzo, Avellion, Verona, Perugia, Grosseto, Alessandria, Sorrento, Empoli
Sarri certainly served his time in Italy's lower leagues before getting his break at Empoli and then his home city club of Napoli in 2015.
A tactical and technological innovator who makes a massively positive impression with his players, Sarri has been lauded for embracing a style of football that is very pleasing on the eye.
No less than Manchester City manager Pep Guardiola described Napoli as one of the most exciting teams to watch in Europe right now and they are leading Serie A at the midway point.
Though he would undoubtedly bring entertaining football to Stamford Bridge, he hasn't coached outside Italy and he hasn't yet won any silverware.
Age: 47 Nationality: Argentine Current club: Atletico Madrid (contracted until 2020)
Previous clubs: Racing Club, Estudiantes, River Plate, San Lorenzo, Catania, Racing Club
Simeone has been linked with a number of top jobs in recent years but will prove difficult to prise away from Atletico Madrid, where he is contracted until 2020.
Hailed for transforming an unfashionable and underachieving team into achievers both in Spain and the European competitions, Simeone certainly isn't short on passion.
His animated touchline antics are pretty similar to Conte's, though his approach tactically may not be to Chelsea tastes.
But guiding Atletico to two Champions League finals, beating a raft of top quality opponents along the way, has confirmed Simeone is a man who can mix it with the best bosses.
Trophy cabinet: (Estudiantes) Argentine Primera - Apertura 2006; (River Plate) Argentine Primea - Clausura 2008; (Atletico Madrid) La Liga 2013-14; Spanish Cup 2012-13; Spanish Super Cup 2014; UEFA Europa League 2011-12; UEFA Super Cup 2012; Champions League runner-up 2013-14, 2015-16
P.S. WHAT ABOUT ANCELOTTI?
Former Chelsea manager Carlo Ancelotti is currently available following his sacking by Bayern Munich back in September, but isn't believed to be in the frame.
He became a crowd favourite at Stamford Bridge after guiding the Blues to the league and cup Double in 2011, and has a proven track record, but there seems to be no desire to have him back again.