The 5ft 7ins 20-year-old midfielder, a standout in a 3-0 winning debut against the Faroe Islands on Tuesday night, said: 'Martin O'Neill had a problem with my height. I had a few meetings with him and the size issue always came up.'
Small wonder: Barry Bannan
And Bannan, denied a debut goal when he saw a first-half strike hit the post, added: 'I was not going to get a chance in the team - no matter how well I did in training.
'Last year I was on loan at Blackpool and only playing games now and again.
'When O'Neill left Villa, I hoped someone would come in and give me a chance and trust me and the last few weeks have been a breath of fresh air for me. Obviously, it has been a big change in fortunes for me.
'Gerard Houllier has come in and has shown great confidence in me, I'm playing in the Premiership for Villa and now the Scotland gaffer has given me a chance.'
Bannan breezed through his debut and yesterday he even had former Scotland boss Alex McLeish comparing him to Arsenal and England prodigy Jack Wilshere.
'Every game I play now gives me more confidence,' continued Bannan. 'At certain times in the past, I was disheartened. But you can't let yourself get that way because, if you do, your game tends to drop.
'I just hoped that some day something would change. Now the manager has changed and everything else has changed, too.
'Houllier wants a passing game and he gave me the nod for the first team after I'd done well in training. It's not just me. It's encouraging to see a lot of young lads coming through now.
'I know I'll have to work my socks off to stay in the Villa team. Hopefully, I'll be able to put together another few good displays.'
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Explore more:People: Martin O'Neill, Jack Wilshere, Gerard Houllier, Alex McLeish Places: Scotland, United Kingdom