Everton midfielder Darron Gibson admits he feared for his career as he recovered from his last knee injury.
He sustained a cruciate knee injury on international duty with the Republic of Ireland in October 2013.
Gibson said: "The lowest moment was the day after my operation. The amount of pain I was in I wouldn't wish on my worst enemy.
"There were a few dark moments to be fair. It has been tough for me and there was a stage when I didn't think I was going to come back.
"Thankfully I have come through the other side and hopefully I will be fit for a long time to come.
"I'm over it now and I don't really want to talk about it. It puts things into perspective. Eighteen months out was hard for me mentally."