Barnes said: "I don't think the Celtic job was too big a job too soon, but unfortunately other people did, which impacted on my performance.
"I didn't get the support. I didn't get the belief from the fans. I didn't get the respect of the players. If I said the same thing as Martin O'Neill, they wouldn't listen to me but they'd listen to him because of what he had achieved.
"Even when we beat Aberdeen 6-0 I was still being questioned about my decisions. Put it this way, I wouldn't have survived on Juande Ramos's results!
"You can ignore the fans shouting at you but you must have the respect and backing of the people you're working for. These people didn't want me, they wanted Kenny (Dalglish).
"But I wasn't bruised at all. I recognised why things happened. If Henrik Larsson hadn't broken his leg, I might still be at Celtic. It was just an experience I went through that was necessary to get me here to manage Jamaica."
He added: "There is no long term in this. It would have been great to get a six-year contract, but I know that if I do well in a few matches and people like me then we can move on from there.
"There are dissenters and you'd expect that on the basis that I've only managed Celtic for 10 months. But I can't afford to concern myself with any negative thoughts. I know I can be a successful manager."