Chelsea manager Antonio Conte has questioned whether the English champions share his ambition as he prepares for Sunday's match at runaway Premier League leaders Manchester City.
Conte, who joined Chelsea in 2016, led them to the league title in his first season but they have failed to challenge this term and sit fifth in the standings, 22 points behind City.
Chelsea's struggles have not been helped by their transfer dealings after they missed out on some of their targets to their Manchester rivals as well as Liverpool and Tottenham Hotspur.
"It's very important to have the coach and the club with the same ambition: to improve the team, the idea of football and the quality of your players," Conte told reporters. "If you find this situation, probably the season will finish with success.
"I have great ambition but I don't have money for Chelsea. The club knows very well what is my idea, what is my ambition... When you decide to work with this type of coach, you must understand that you take a coach with great ambition."
Chelsea are battling for Uefa Champions League football next season but defeat at City would leave Conte's side five points adrift of the last qualifying spot if their fourth-placed London rivals Tottenham Hotspur beat Huddersfield Town on Saturday.
Conte believes Chelsea have failed to sufficiently improve the squad after last season's triumph, saying that City had wrapped up the title in the first half of the current campaign.
"Last season we did a fantastic job. We were a great surprise... But then you have to continue to build something important with the coach," Conte added.
"Manchester City won it (this season's title) in that first part of the season. This must be a great frustration for me, for my players, for my club. If your name is Chelsea, you have to try to fight until the end."
The 48-year-old Italian also backed big-spending City to strengthen further under manager Pep Guardiola.
With Conte's future uncertain at Chelsea as he struggles to repeat the success of his first season, Italian Football Federation (FIGC) vice-commissioner Alessandro Costacurta has said he is the primary choice to return to the national team.