Chelsea manager Andre Villas-Boas has acknowledged that his side's recent results have led to doubt over his tenure at the club.

The Blues have gone five games without a win and are on the verge of being eliminated from the Champions League following their 3-1 defeat to Napoli on Tuesday.

Villas-Boas has continuously insisted that his job at Stamford Bridge is safe, but does recognise that football is a results-based business.

"Everything is always related to results," Villas-Boas said.

"The problem is that results lead you into doubt so are you able to live with that climate of doubt and believe in the person and the project, or do you believe the person is not the right one?"

Chelsea have dropped down to fifth in the Premier League after their recent poor form, level on points with fourth-placed Arsenal.