Chelsea's title wobble: Alonso absence and Costa concerns for Conte
The mood around Stamford Bridge had shifted significantly after Sunday's loss to Manchester United, but how should Chelsea supporters be feeling?
ESPN FC runs through five reasons to be confident and five reasons to be anxious as the Premier League title race reaches its decisive final weeks.
Reasons to be optimistic
1. Chelsea have an easier run-in than Tottenham
Conte's claim that Chelsea now have a "50 percent probability" to win the title is simply a motivational line for his players. The reality is that Tottenham are still very much the underdogs.
Chelsea have four of their final six Premier League matches at home, while four of Spurs' last six are away. The two at White Hart Lane are against Arsenal and Manchester United. Admittedly, the Gunners are in crisis and Jose Mourinho has no incentive to hurt Tottenham's title bid, but there are also significant challenges elsewhere.
Away games against Crystal Palace, West Ham and Leicester City, none of whom are mathematically safe yet, are unlikely to be easy, while Hull City should need a result when they host Spurs on the final day.
The only relegation battlers Chelsea have to face, Middlesbrough and Sunderland, are virtually doomed and none of the Blues' other opponents have more than league position to play for.
Not for the first time this season, the fixture list appears to be Chelsea's friend.
2. This team reacts well to defeats
Chelsea have not lost back-to-back Premier League matches since September, before the switch to 3-4-3. After losing 3-0 to Arsenal they embarked on a run of 13 straight wins and when Spurs ended it at White Hart Lane in January, they went a further eight games unbeaten. The 2-1 loss at home to Crystal Palace was answered with a convincing win over Manchester City three days later.
3. Few teams will be able to do what United did
It took a trademark Mourinho game plan and badly timed misfortune befalling Thibaut Courtois and Marcos Alonso to make Chelsea look as lacklustre and toothless as they did at Old Trafford.
It's unlikely that every team Chelsea face from here on will detail two men to track Eden Hazard and Pedro Rodriguez all over the pitch. Even if others try, very few will be able to do it as effectively as Ander Herrera and Matteo Darmian managed.
4. Alonso not a long-term absentee
Chelsea really missed Alonso at Old Trafford. His importance to this 3-4-3 goes beyond his particular skills as a player; he and Victor Moses create the width and overload situations that make Conte's attacking system tick.
Fortunately for Chelsea, Alonso's absence was due to a virus rather than an injury. He will be back sooner rather than later.
5. They have the Premier League's best player
For all of Mourinho's tactical wizardry, much of Hazard's ineffectiveness at Old Trafford was down to Alonso's absence and him having a bad day. The Belgian is the best attacking weapon in the Premier League and has largely played like it in 2017. As long as Chelsea have him fit and firing, they will take some stopping.
Reasons to be anxious
1. Tottenham are in top form
Spurs have won seven Premier League games in a row and the performances have been ominously good. They have the best defence in the division and at the other end, Harry Kane and Dele Alli are match-winners.
The only significant absentees are Harry Winks and Danny Rose. The latter could still return before the end of the season.
2. Fragile balance of Conte's 3-4-3
Chelsea were always going to struggle a little without Alonso, but the extent to which United shut them down will alarm Conte.
Fewer games and even fewer significant injuries have meant the Italian has not needed to delve into the fringes of a squad he doesn't fully trust. Chelsea have no reliable replacement for Alonso, but the same can be said for David Luiz, N'Golo Kante and Hazard. What if injury takes one of them away?
3. Diego Costa's bad form
Costa's form is a huge problem for Conte. The Spain international has scored four goals in 13 matches in all competitions since receiving a lucrative offer from Tianjin Quanjian. Even more worryingly, he is no longer acting as an effective "reference point" for Chelsea's attack.
Costa's last assist came against City on Dec. 3, and his key passes have slumped to virtually zero. Add that to the returning indiscipline and he is a total passenger.
Conte either has to find a way to bring back the Costa of 2016, or put him on the bench. Chelsea can no longer carry anyone.
4. Defensive levels have slipped
The run of 10 clean sheets in 12 games from October to December that powered Chelsea's rise to the top of the table feels like a long time ago.
That level of solidity was unsustainable, but every one of the Blues' past 10 Premier League opponents have found a way through. Misfortune has played a part but the pattern of defensive decline is now too compelling to ignore.
Title-winning teams are built from the back, and Conte will need to be able to rely on his defenders down the stretch.
5. Footballing karma
Plunging the dagger into Tottenham's faltering title challenge was the only redeeming moment of last season for Chelsea supporters, but in football, schadenfreude has a habit of evening itself out.
Whether or not you believe in karma, nothing would be more poetic than Tottenham making up for last season's bitter disappointment than capitalising on an epic Chelsea choke to claim the Premier League title in the final weeks.
It's a powerful narrative, and Spurs fans won't be the only ones desperately hoping it comes to pass.
Liam is ESPN FC's Chelsea correspondent. Follow him on Twitter: @Liam_Twomey.