Leigh Griffiths is set to seal a bumper new Celtic contract and has blasted back at the online trolls who claimed he had failed a drugs test last week.

The Celtic striker was hospitalised with tonsillitis and a viral infection and only returned to training on Thursday morning.

However, he took to social media to hit back at those who had claimed his absence was due to more sinister reasons, insisting that it was too difficult to sit on his hands as rumours about his character took hold.

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“It was madness, what I was reading,” he said. “I had to laugh at the stuff people try to make up but it’s not nice for my family to see. They all read that nonsense and it’s disgusting, some of it.

“The people who put this out there, that’s their life. If it makes them happy putting out rumours and it’s what they want to do…I prefer to ignore what they’re saying and concentrate on the real world.

“These people are sad individuals. They don’t see the light of day; they just sit behind computers or mobile ‘phones and try and make up rubbish to disrupt other people’s lives.

“I’ve learned to grow a pair and just ignore them but I had to say something on this occasion but when there are rumours going around that I’ve failed a drug test and it’s being swept under the carpet then I have to come out and say something because if I sit in silence then that lie gathers more and more momentum.

“I felt I had to put this to bed so that it was quashed and nobody would speak about it again.”

Griffiths is poised to sign an extension to his current deal with Celtic. The forward has another two years to go but there have been ongoing negotiations to tie him up on the long-term, something he hopes to complete before the curtain comes down on the season.

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“Talks are still ongoing,” said striker. “My agent just texted me before I came in here, so I’m hoping there will be a bit of news before the season is out. I’ve still got two-years left, so I am not sweating over it. I’m still looking to commit my long-term future here but these things are never easy, these things take time.

“We need to iron out every detail but I’m hoping it’ll be done before the season is out. I’m happy with my football here, when I am playing and scoring goals there is no place I’d rather be.”

The recent illness is the latest issue for Griffiths who has had a campaign that has been undermined by injury. The striker sought specialist advice for a recurrent calf injury earlier in the season and he has acknowledged just how frustrating it has been over the last ten months.

Griffiths, named as the Scottish Football Writers’ Association’s International Player of the Year, is optimistic of getting some game time under his belt on Sunday as Celtic are presented with the league championship.

“I’m still a bit under the weather but I’ve been given medicine from the hospital to take and it’ll pass,” he said. “Anyway, there are only a couple of games still to go and then I can have a proper rest.

“I didn’t even feel rough. I don’t know what it was, just a bad infection. Last Sunday took its toll and that’s when the doc called me and told me to get to a hospital and I was admitted overnight.

“They did various tests on me but they came back all clear and I just wanted to get out so I could return to training and playing. It really affected my energy levels, though, and I feel physically weak. I also lost a lot of weight and I’m finding normal training sessions a bit hard.

“Obviously, I haven’t been able to play to my full potential this season so it’s nice to pick up this award. It’s been frustrating for me – I’d rather miss games through illness than injury but since I’ve been available to train again I haven’t missed a session and that’s credit to the medical team and the specialists I’ve had to see to fix this problem.”