Chelsea manager Antonio Conte has admitted that he is "worried" by Manchester City's "incredible" form in the Premier League this season.
City came from behind to battle past Huddersfield Town at the John Smith's Stadium on Sunday and record their 11th consecutive Premier League victory, restoring their eight-point lead at the top of the table in the process.
Chelsea, meanwhile, find themselves 11 points adrift of Pep Guardiola's runaway leaders, and Conte suggested that the January transfer window could be key to their fading hopes of catching City.
"Manchester City's path is incredible, no? I think Manchester City in this season is a strong team. Also last season, Manchester City was a fantastic team. Then, after the transfer market, they bought their first targets and then they have improved a lot," he told reporters.
"They can do this also in January maybe, in the future. For this reason we must be worried because if we want to compete with Manchester City we have to work and then make the best decisions in the transfer market."
Chelsea are back in action again on Wednesday night when they host Swansea City at Stamford Bridge.