The England international lasted just 15 minutes of the Blues' 2-1 defeat at Shakhtar Donetsk on Tuesday after suffering a recurrence of the calf injury that kept him out of the Three Lions' recent World Cup qualifiers.
The 34-year-old will undergo a scan on Wednesday, and manager Roberto Di Matteo is hoping for the best.
"It's basically a recurrence of an old injury," said Di Matteo.
"He was training with us fine and there were no alarm bells before the game. He was in good condition to play."
Chelsea host Manchester United in the Premier League at Stamford Bridge on Sunday.