Neil Lennon says Celtic will need to be disciplined defensively against Barcelona at Camp Nou as it's "the most difficult place" in Europe to get a result.

The former Hoops boss was speaking ahead of the Scottish champions' Group C opener against the Catalan giants in the Champions League.

Lennon himself enjoyed mixed fortunes against Barca as a manager, recording an historic 2-1 victory over the Spaniards at Celtic Park in 2012 before being defeated 6-1 in the Camp Nou a year later.

Celtic have been rampant domestically under boss Brendan Rodgers, scoring goals for fun and putting five past Rangers in the build-up to Tuesday.

However Lennon says it's at the back where they will need to sharpen their focus.