It will be the start of a new era at Stamford Bridge on Saturday as Chelsea host Sunderland in their first fixture following the departure of manager Jose Mourinho.
The Portuguese guided the team to their first domestic title in 50 years during his first season in charge in 2004-05, successfully defending the trophy the following season.
After successful stints at Inter – where he won the treble – and Real Madrid, Mourinho retook the reins in west London in 2013.
The 52-year-old led Chelsea to the Premier League trophy in 2014-15, but this term they have struggled badly for form, already losing nine top-flight matches – equalling the amount of defeats they suffered in the past two campaigns combined.
It has been a season fraught with controversy for Mourinho, and a 2-1 loss against Leicester City on Monday proved to be the end for the manager, who parted ways with the club by mutual consent on Thursday.
The Portuguese leaves the defending champions 16th in the Premier League, one point clear of the relegation zone and with just one win in their last seven attempts.
Mourinho has got the better of former Bolton, Blackburn, Newcastle and West Ham manager Sam Allardyce in seven of their 10 Premier League encounters, with the spoils shared on the other three occasions.
Now the Sunderland manager, Allardyce is disappointed he will not have the opportunity on Saturday to finally get one over Mourinho, labelling his exit a loss for the English game.
"I'm sad to see Jose go. One, because I got to know him quite well and, two, he's a great manager with great character and he's a loss to the Premier League," Allardyce said.
"Only time will tell on whether there's a better performance, or reaction, from the players than while Jose was in charge.
"It's a pretty bad indictment on the players if they perform better than they have done recently just because Jose has lost his job, but, who knows, there seems to be that reaction sometimes from a squad of players.
"Because of the underachievement that's happened at Chelsea, even a great manager like Jose has lost his job, and that shows you we are all in the business of results when we manage a football club."
Eden Hazard is a doubt for the meeting after limping off with a hip injury in the defeat at Leicester, while Radamel Falcao is unlikely to overcome a muscle issue in time to feature.
Sebastian Larsson (knee) will miss out, but Allardyce could call on Younes Kaboul, who missed the 1-0 defeat to Watford through illness, while Lee Cattermole may return from a back injury.
Key Opta stats:
- Chelsea have won 18 and lost just two of their last 21 Premier League games against Sunderland.
- In four of the last five Premier League games between Sunderland and Chelsea, the team who scored first ended up losing the match while the other ended 0-0.
- Sunderland have allowed their opponents a league-high 99 shots on target in the Premier League this season.
- Diego Costa has scored just three goals in 13 Premier League appearances this season – in his first 13 top-flight appearances of 2014-15 he had netted 12 goals.
- Sunderland (10) have picked up more points than Chelsea (7) in the Premier League since the start of October.
