Manchester City midfielder Fernandinho has warned his team-mates not to underestimate Sunderland, even though a crunch clash with Premier League leaders Leicester City is fast approaching.
City meet Sam Allardyce's men on Saturday, before facing title rivals Leicester on December 29.
But Fernandinho does not want City to look too far ahead, pointing to the fact Sunderland have always given Manuel Pellegrini's side a stern examination despite often struggling against other teams.
"Anybody who believes playing Sunderland at home will be easy is mistaken," he told the club's official website.
"I remember two seasons ago when we were going for the title and they held us 2-2 and last year, on New Year's Day, they made it really difficult again, though we eventually won 3-2.
"They always seem to play well when they are up against us - maybe they just play this well against City! But now they will come here having changed their manager and with the extra motivation.
"We need to prepare well, concentrate throughout and give our fans the kind of performance they deserve."
Fernandinho also understands the importance of Boxing Day fixtures in England and does not want a poor City performance to spoil the festive season for their supporters.
He continued: "I knew when I came to City that playing on Boxing Day was a special day for supporters in England and maybe one of the most-looked forward to on the calendar.
"It is a day when people are relaxed and with their families and we need to prepare correctly and make sure we send our fans home happy so they can continue to enjoy the holidays.
"We will be doing our best against Sunderland, I can assure everybody of that."
City are third in the Premier League, while Sunderland are down in 19th position.