The Blues face the Russian side at Stamford Bridge on Thursday evening hoping to gain an advantage in the first leg of the sides' last-eight meeting.
But Capello, who is now in charge of the Russia national team, believes that Rafa Benitez's men are in for a tough test.
|14/1||Chelsea are 14/1 with Coral to lose 1-0 to Rubin Kazan in their Europa League first leg|
"Chelsea need to be careful when they play against Rubin Kazan because they've got good spirit, good organisation and also good players."
Benitez's side are set to complete seven fixtures in the month of April due to their participation in the FA Cup, Europa League and Premier League.