John Obi Mikel is hoping Chelsea can avoid being struck down by another case of the winter blues.
The Stamford Bridge outfit have made a habit of suffering a seasonal slump towards the end of the calendar year.
A 2-1 UEFA Champions League defeat to Shakhtar Donetsk on Tuesday arrived at a time in which the Blues have started to hit the skids in recent seasons.
That loss was, however, their first major setback of the season and Mikel is confident Roberto Di Matteo's side can offer a positive response - starting on Sunday in a crucial home date with Premier League title rivals Manchester United.
The Nigerian midfielder said: "All of us know what has happened in recent seasons, so we have to make sure that this defeat doesn't make that happen again.
"We have to make sure we correct it very quickly and that starts with the next game against United.
"They will be very dangerous as usual and, if we defend the way we did (against Shakhtar), it's going to be difficult for us.
"We have to defend as a unit, play together as a unit. As long as we do that on Sunday, we'll have a very good chance."
Branislav Ivanovic is also looking for Chelsea to bounce back against United, with the versatile defender conceding that the Blues allowed their standards to slip against Shakhtar.
He said: "We have to analyse it well and see where we made the mistakes.
"These things are down to concentration and preparing for the game. We have to start well and be focused for the whole 90 minutes.
"This is the change of the team. We defend as a team and we attack as a team.
"We have to stay together and be more compact in this type of game. That makes it easier for your team-mates.
"Of course, a result like that has an effect on morale but this is one of the most crucial games of the season.
"We've had two difficult games, at Spurs and Shakhtar, and now we have to recover and prepare well for Sunday."
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