“The manager is bonkers – and you can write that. He is bonkers," he told the Record. “He’s just uninspiring.

"He just saps the life out of the players. That’s the biggest problem at the club. They chose the wrong guy."

But McDonald did have words of praise for his old Celtic boss Gordon Strachan – despite being dropped by the Scot when he was a youngster at Southampton.

He also revealed how close he had once come to signing for the Bhoys' deadly city rival Rangers in 2007.

"I was already well liked by the Rangers supporters and I’d given up hope of signing for Celtic," he revealed. "So this was an opportunity to take my career to another level.”

Motherwell at the time refused to sell the former Gippsland Falcon star, and a year later an offer came in from Celtic instead.

“I got a call saying Celtic were interested and I didn’t believe it," he admitted. "I was then told to wait for another call from Gordon Strachan.

“It turned into the longest 10 days of my life. I was in Hong Kong with the national team when the phone eventually did ring. I was so nervous I could hardly speak. You have to remember the guy on the other end of the line released me when I was a kid at Southampton.

“So this was awkward from the start. After some small talk, he says: ‘Are you going to have a problem working with me because I got rid of you?’.

"There had been a lot of disappointment when he let me go. A lot of hatred. To me he was a little ginger so-and-so!

“It was only when I got older I realised why he had done what he did. He knew I wasn’t ready. I had to go away and become a man. At the time I was angry.

“As a young boy it doesn’t even occur to you that some of the things he’s saying might actually be right.

“You are striving to get to the top and this guy is just getting in your way. As it turned out moving to Motherwell was the best thing I could have done.”

He added: “But our relationship totally changed when he phoned me before I stepped in the door at Celtic Park. How many managers do you think would go and rectify a decision they had made, regardless of how good that player had gone on to become?

“Essentially he didn’t say he had called it wrong. But he did say, ‘You weren’t as good then as you are now’. Maybe he twisted it to his own advantage. But that phone call told me a lot about him as a person. I couldn’t wait to work for him.

“Sometimes everything just falls into place. It was a marriage made in heaven. There were no low points under Gordon, none."

Strachan left and was replaced by Tony Mowbray – and everything changed for McDonald, he said.