The Scot described the pitfalls as 'nightclubs, alcohol and girlfriends', but national identity was also proving to be a tense issue.
He said: “I had Jack in the office several times for a good telling off, one in particular for not turning up to training.
“Then the Irish thing came up. He seemed pretty torn. I didn't want him to make the wrong decision.
“You have to be comfortable playing for an international side. All I was saying was 'watch yourself'.
“He might turn around today and say 'Paul Lambert was a real s**t' or may understand. I thought he had too much on his plate too soon.
“I was trying to guide him. I hope he sees that now."