BRENDAN RODGERS has warned his Celtic defenders to be extra vigilant against Zenit St Petersburg tomorrow night.
The Hoops boss has told them a split-second loss of concentration against the dangerous Russians could mean an exit from the Europa League at the last-32 stage.
Two lapses by Jozo Simunovic at the weekend threw Partick Thistle a Scottish Cup lifeline before a hat-trick by James Forrest saw the holders hold on for a 3-2 triumph.
Dedryck Boyata is out through through injury and Rodgers is likely to again partner teenager Kristoffer Ajer with the Bosnian international.
Assistant gaffer 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 to ensure we are defensively solid.
“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 players the important of defensive organisation, concentrating on being hard to beat.
“We know we have threats going the other way.”
Rodgers will also be without Craig Gordon, Leigh Griffiths, Patrick Roberts, Tom Rogic and Stuart Armstrong, among others.
Despite again making it through to the group stages of the Champions League, Celtic failed to take a point from their three home games with Paris Saint Germain, Bayern Munich and Anderlecht.
And Davies acknowledged the team must give the supporters something to feed off.
He added: “The crowd are fantastic and, as we have said before, there is no better place to play than Celtic Park in Europe.
“The atmosphere they generate is incredible. It’s up to us that it inspires us and it intimidates our opponent. So we have to use the atmosphere.
“The reputation of Celtic Park will never go away. We’ve got to focus and use that as inspiration.
“We have to make sure we are concentrating on the game and not thinking too emotionally but tactically, and then it will start to intimidate the opponent.’