John Obi Mikel admits Chelsea must be fully focused and avoid committing any errors if they want to beat Watford on Boxing Day - while also ensuring they deal with the threat of Odion Ighalo.
The champions host Quique Sanchez Flores' Hornets side on Saturday afternoon, a team who will arrive at Stamford Bridge on a four-game winning run.
Ighalo has proved important in Watford's rise to seventh place in the Premier League standings, having scored 12 league goals for the promoted club this season.
And his compatriot Mikel is remaining wary of the threat the Nigeria international could pose at Stamford Bridge, but believes Chelsea will be able to secure all three points against Watford if they can score early.
"They are in good form, they have been promoted into the Premier League and they are surprising everyone playing the way they are, so we have to be on our A game," Mikel told Chelsea's official website.
"We have start the game well and if we can get a few goals that can help settle us down.
"I am not surprised Odion Ighalo is doing what he is doing. I have chatted with him and played with him in the national team and I can see the talent he has, and even before I have the ball in those games he is already making his run.
"He is a player who likes to exploit the space behind the defence and is a good finisher around the box. He is someone we need to watch out for."
Chelsea currently sit in 15th place in the table - 10 points behind Watford and 11 behind fourth-placed Tottenham.
Despite former manager Jose Mourinho having ruled out the club's chances of finishing in the Champions League spots this term, Mikel insists that aim remains within the champions' grasp.
"We have to win every game now. The top four is still achievable, we can still do it so why not? It is not beyond our reach," he said.
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"The cups are always important as well. We are still in the Champions League, the FA Cup is going to start very soon so we have to take those very seriously at the same time, but we also want to concentrate on the league because we know we have to push up the table."
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