Celtic assistant John Kennedy has opened up on the horror tackle that ended his career for the first time.

The 40-year-old suffered the injury on his Scotland debut against Romania in 2004 and it kept him out of football for three years.

Kennedy had previously earned rave reviews for his performances against Rangers and Barcelona under Martin O'Neill.

Speaking to the Celtic FC podcast, he said: "I still remember it very clearly in terms of the game itself. 

"I remember the tackle and thinking 'something has happened here'. You almost go into a state of shock when you get such a bad injury.

"I remember saying to the physio 'just get me up' and they were kind of tentative. I remember pulling myself up onto my feet a little bit and the first step I took my whole leg just buckled.

"I thought my leg was broken and I said to the physio, 'my shin has snapped' and I remember seeing my leg had moved to the outside.

READ MORE: Celtic's Brendan Rodgers has more to do to match predecessor

"I kept saying 'my shin has snapped, my shin snapped' and we waited till the stretcher came. I then went to the hospital and I remember the doctors sounding concerned but they could not do anything till the next day until I got a scan."

Kennedy also detailed how he has used his injury as a warning to young players.

"When you are young, you feel untouchable, particularly when you are riding the crest of this wave and everything is going well," he continued.

"It was a life lesson that things can come crashing down at any given moment and they did for me.

"It is something I still use in a coaching capacity at times. My experience is take nothing for granted in terms of what you have.

"Make the most of things because on any given day things can change. I tried to come back, and had moments through that period, but could not get back to the level I wanted.

"I always had a struggle to keep things going. The doctor told me after the scan, 'I have never seen anything like this'.

"It was such a horrific injury."