Aston Villa midfielder Stiliyan Petrov believes Chelsea haven't recovered from the departure of Jose Mourinho.

"When Mourinho was there they had a special team," said the Villa midfielder, recalling the back-to-back Premier League titles Chelsea won under the Portuguese in 2005 and 2006 and the winning mentality he instilled in his players.

"I think they had more belief in themselves. I don't think Chelsea are the team that they used to be under Mourinho. A lot of changes have happened there."