CHARLIE MULGREW'S season may be over after he was risked against Ajax on Thursday night.

The Scotland international made his first appearance for over two months as a substitute and was last seen limping off the pitch with a recurrence of his quad injury.

Mulgrew took to social media to explain why he walked off before the end of the game, something he was criticised for, and even use the phrase "career threatening" to explain his situation.

His assistant manager John Collins revealed the 29-year-old was only named on the bench because of the team's selection problems. It was a decision that badly backfired.

Mulgrew said: "For those who think I walked off the park in a huff...can't be serious?

"I've re-injured (sic) my quad. I'm devastated after being out so long and working hard to get back."

And then he added: "I got the original injury against Aberdeen with 3-4 mins to go, stayed on and made the injury worse.

"Tonight I was running back from the corner and felt something go again, so wouldn't have been able to even jog about the park without making things worse.

"I've played through knocks and injury many times for Celtic, but until you've tore a tendon and realise what it feels like and how playing can be career threatening, then you don't know.

"Looking back I maybe should have sat in the dugout, but my head was gone.

"I'd worked hard to get back and I was/am devastated facing time out again, especially after last year's tendon injury in my hamstring that kept me out for six months."

Mulgrew is likely to be out for some time, which is a blow for his team who could use his experience in the absence of Scott Brown.

Collins said: "Unfortunately Charlie’s injury has come back. Poor guy. I feel for Charlie who is devastated. His thigh has kept him out for three months.

"He declared himself fit. Ideally we would have had a few reserve games and if we had had more men fit then he wouldn’t have been on the bench.

"We thought his experience to come on in the last 15 minutes would calm things down, which he did, when he showed composure and calmness.

"I don’t know how long he will be out for until he has the scan.”