Demba Ba faces eight months on the sidelines after suffering a broken leg playing for Shanghai Shenhua.
Ba, who joined Shanghai from Besiktas last summer, has scored 20 goals in 29 games for his new employers.
The striker suffered a career-threatening injury on Saturday however, during the club’s 2-1 victory over bitter rivals Shanghahi SIPG.
Ba was rushed to hospital and placed under general anaesthesia, awaking four hours later in considerable pain.
According to medical staff, the first question the 31-year-old asked: “Did we win the game?”
“It could end his professional career,” said coach Gregorio Manzano. “I would rather lose the game than lose Ba.”
All at Chelsea FC send our best wishes to former striker @dembabafoot. Get well soon Demba.
— Chelsea FC (@ChelseaFC) July 17, 2016
Former Chelsea teammate John Terry added: “Terrible news to hear of Demba Ba’s injury today. Wishing you a quick recovery mate.”