CELTIC star Mikael Lustig has revealed he needs to pop painkillers before every game because of his swollen foot.

And the Swedish defender admitted that it could take a year before he is fully fit again, as he has not fully recovered from damaging his ankle ligaments in February.

Right-back Lustig insisted he could still “give 100 per cent” and is expected to start tomorrow night when the club’s quest to reach the group stages of the Champions League begins in Glasgow against FC Stjarnan of Iceland.

Lustig has suffered several smaller injuries since joining the club in January, 2012, however, when fit he has been one of the most consistent performers for first Neil Lennon and now Ronny Deila, so his manager will hope the Sweden international can carry on as normal despite his on-going problem.

Lustig said: "I can give 100 per cent, but the foot is still quite swollen.

"They say it's going to be like that for a while so I just need to go through that. I am ready to go. It could be up to a year before it's back to normal but it could be worse.

"It is my ankle ligaments and, of course, I don't feel 100 per cent, but I can give 100 per cent.

"I take painkillers when we play games but not for training. I try not to do that. I have trained now for three weeks and it's getting better.

"It's been frustrating. I got some muscle injuries at the start of last season. When I got my second one, I thought 'I need to do this properly and take a couple of weeks extra.' I did that but then after two games I got the foot injury and was a little bit unlucky."

Lustig is determined to put his foot problem to the back of his mind to play a part in getting Celtic back into the Champions League group stages.

His side should have more than enough about them to see off Stjarnan and will be seeded in the following two round, which gives them a better chance of success.

But Lustig warned his team-mates to learn the lessons of last time when defensive errors proved their downfall.

He said: "I think we were a little too naive in Europe last season,

“If we missed passes we got punished more than we do in the Scottish Premiership. You need to win the game in Europe. An SPL team may go with 10 men (behind the ball) but in Europe the other team has to score.

“But we are going to be more up for it this season and not as naïve. I just remember the first game away against Legia, we gave away two or three passes in the middle and they punished us with goals. We can’t do that again.

"If we play as we can, they shouldn't be able beat us but it's football and crazy things can happen. But no, of course, we are going to go through this round."