BRENDAN Rodgers has told his defenders to get their act together as they prepare to return to the European arena.

The Celtic manager has not been happy with the defensive display in each of the last two matches – Kilmarnock away when they lost for only the second time domestically and Saturday’s Scottish Cup tie with Partick Thistle when Jozo Simunovic gifted Kris Doolan a goal.

He has been impressing the importance of staying switched on because he knows that one lapse could be so costly against a team like Zenit St Petersburg.

Assistant boss Chris Davies said: “The manager has been reinforcing to them the concentration aspect. It’s really important at this level, when you are facing teams like Zenit it can be about that mental fatigue.

“You need to concentrate, be switched on and alive, for every single moment of the game.

“That’s going to be very important on Thursday to ensure we are defensively solid.

“You can work on it in training. Domestically we are used to having a lot of the ball, then you come in to Europe and you are not the team with most of the ball.

“It’s something you look at in training and try to help the players. The manager has been reinforcing to the player the important of defensive organisation, concentrating on being hard to beat.

“We know we have threats going the other way.”

Davies is not sure why errors have begun to creep into Celtic’s play since the winter break but he knows they have to be eradicated at Celtic Park tomorrow night.

He added: “There’s never usually one thing, it can be a combination of factors. It might be there’s an individual lapse. It can happen in football, it’s about making sure you learn from it and don’t make the same mistakes again.

“Sometimes it’s the opposition showing that bit of qualify finishing off the chances they wouldn’t normally.

“As a team it’s about closing down the spaces quickly. These are the things we are looking to address to make sure we are defensively sound.”