Nigeria international Efe Ambrose says Celtic will raise their game when they host Spartak Moscow on Wednesday night in the Champions League.

Lately, the Glasgow giants are struggling for form in their home games, and have failed to win at Celtic Park since October 30.

''Wednesday night is a Champions League game which we know we have to win to get a place in the last 16 because we are not counting on Barcelona to do the job for us.

"We have to do that at Celtic Park. I believe the atmosphere will be different to the one against Arbroath.We have been playing well outside Celtic Park and winning games so I don't really know what is going on at home.

"We are all disappointed. It has been quite long now without a (domestic) victory at home,'' Ambrose was quoted as saying by heraldscotland.com.

Efe Ambrose has suited up four times in the Champions League for Celtic.