1) John Terry's nightmare return
Terry was brought back into Chelsea's starting line-up for his first league appearance since the 3-1 loss at Everton , but it didn't go well. The Blues have now conceded 13 goals in the five Premier League matches Terry has started this season, and only four in the three he didn't start.
The former England captain seemed to be doing well in the first half. Dealing with the aerial threat of Graziano Pelle played to his strengths, and he received some protection from the midfield as Chelsea dominated possession. But things went badly wrong in the second half when Southampton counter-attacked at will, running straight through Chelsea's midfield. Terry looked ill at ease and was left helpless on the floor after his failed interception allowed Sadio Mane to put the visitors in front.
He was then left exposed for the third goal as Chelsea lost the ball with left-back Cesar Azpilicueta upfield. Terry didn't have the pace to stop the attack, and Pelle was free to score. He managed 3 interceptions, made 3 blocks and 2 clearances – winning 2 out of 3 aerial duels – but didn't attempt a single tackle.
2) How Chelsea failed to shackle Sadio Mane
The Blues have now conceded more goals after eight games of this season than they did in the 38 games of Mourinho's first title-winning campaign in 2004/05. Undoubtedly the defence has been a major problem, but they aren't being helped by their midfield when the going gets tough.
Some players are in a difficult moment and Matic is one of them; he is not playing well
The Portuguese's gameplan was for Ramires to man-mark Mane, with the aim of preventing the Senegalese from using his pace to run at Terry and Gary Cahill. The plan worked up to a point in the first half, but then fell apart: Ramires completed only 3 of 6 attempted tackles, and was fortunate not to concede a penalty when he tripped Mane inside the box. Then came possibly the turning point of this game – his yellow card for a foul on Mane just before half-time. Saints equalised and the booking left Ramires walking on a tightrope, rendering his defensive task almost impossible.
As a result, Mourinho substituted the Brazilian at the interval, replacing him with Nemanja Matic. But that didn't work either, because Mane ran riot in the second half, netting Southampton's second goal. Matic was sensationally substituted himself at 3-1 only 28 minutes after coming on, when Mourinho brought on an extra striker in Loic Remy as he sought a way back into the game. The gameplan had backfired spectacularly, and Matic's withdrawal sparked boos from the crowd.
"It was not to humiliate anyone, I don't do that to anyone," Mourinho said of the substitution. "But some players are in a difficult moment and Matic is one of them; he is not playing well, he is not sharp defensively, he's making mistakes with the ball, not the best decisions. I played him because Ramires was doing a great job on Mane but with a yellow card and an inexperienced referee I was afraid of a second yellow card."
In total Mane had 4 shots, completed 4 of 6 take-ons and created 3 chances. "Sadio was very dangerous with his movement, it was impossible to defend well against him," his manager Ronald Koeman said afterwards.
3) Mourinho going on the defensive
December, January, we will be top four. To be champions will be very difficult
There were boos when Matic was substituted and boos before that when Willian was brought off, illustrating the changing mood around Stamford Bridge after Chelsea's poor start to the season that leaves them 16th in the table – 10 points behind leaders Manchester City. Mourinho has rarely faced such criticism from his own fans before and he was on the defensive after the match, urging Roman Abramovich to trust him and explaining that Willian was brought off because he was ill.
"No way I resign because Chelsea cannot have a better manager than me," Mourinho said. "I have my professional pride and I know I am very good at my job. I want the best for my club and the best for my club is for me to stay. When we were champions last season I said I am going to stay until the day owner and the board want me to leave. I said that when I was champion and I say that now."
Asked if Abramovich still backs him, he said: "I have no signs that anything has changed. Every time the results were not good there was a change of manager in the past. But when I was contacted to come back, I was told 'We had so many managers, we know you are the best'. I think it is time for the club to act in a different way, to act in a position of stability, a position of trust.
"Three months ago we were all together in the bus with the cups so it is time for us all to be together now in the bottom of the league. December, January, we will be top four. To be champions will be very difficult."
Chelsea did have 61% possession, with 438 completed passes to Southampton's 257. But the Saints' play produced 13 shots to Chelsea's 10, and the Blues also misplaced a rather hefty 115 passes. Worst of all, they barely looked like turning the tide after half-time when Koeman's side forced their way back into the game.
4) Willian, the new free-kick king
Willian hasn't always hogged the headlines at Stamford Bridge – indeed, it looked like he might have been replaced when Juan Cuadrado arrived last January. But Cuadrado swiftly came and went, while Willian has remained to become one of the few Chelsea players to emerge with any credit in recent weeks.
He has now, incredibly, scored with a free-kick in each of his last four appearances; against Maccabi Tel Aviv, Newcastle, Porto and now Southampton. Like his recent goal at Newcastle, this was an angled effort aimed at the far post that may have been as much a cross as it was a shot. As it was, it looped over the head of Maarten Stekelenburg into the net, almost Ronaldinho-like.
5) Blues toothless without Costa
The one good piece of news from this match is that Diego Costa's suspension has now been served, and the striker will be available for the home game against Aston Villa on October 17.
Radamel Falcao started up front against Southampton, getting the nod ahead of Remy, but proved an inadequate replacement for Costa. Once one of the most prolific strikers in world football, Falcao has now scored only seven goals in 23 months, having failed to regain form since a serious knee injury.
Like Fernando Torres before him, Falcao looks to have joined Chelsea on the way down, unable to recapture former glories. He was booked in the second half for simulation as he went down under a Stekelenburg challenge. Mourinho felt it was a penalty, but Falcao seemed to initiate the contact rather than the keeper.
The Colombian had only one shot, which was blocked, completed just 22 of 32 passes and won only 4 of 10 aerial duels – something that was once his strength. We would say maybe the new short hair is having some sort of Samson effect. But then we remember how he played for Manchester United.