Former Derby County player has admitted his shock after being drafted into the 23-man outfit as a replacement for Keith Fahey
The central midfielder, who is without a club after turning down a new contract at Derby County, was a late addition to the squad when he was called up as a replacement for the injured Keith Fahey.
Green told the Irish Independent that he was shocked at news that he had been called up to Giovanni Trapattoni's 23-man outfit.
He said from Ireland's pre-tournament training base in Montecantini: “I couldn't believe it at the time and I was so surprised."
Green later told RTÉ: "I never thought I would be here. I am absolutely delighted to be here and hopefully I can get involved at some time in the championships."
Prior to his inclusion in an Irish training camp in May 2010, Green was somewhat of an unknown quantity to Ireland fans, but he has proven to be a favourite of Trapattoni. The manager started the midfielder in Ireland's opening qualifying games before injury ruled him out of later fixtures.
And despite the faith invested in him by one of the world's top coaches, Green has yet to win over Ireland fans, but the former Doncaster player hit out at his critics.
“Everyone is allowed their opinion,” he said. "I think I can cope at this level. I don't think the manager would have me here if he didn't think that.”
Ireland's current manager has consistently praised Green's contribution to the team and hinted that he may play a part against world champions Spain.
“Green can do this, stop others playing, and that is important for us. He has this quality and against Spain it is what I need maybe," said Trapattoni.
Meanwhile, Green is hoping his late addition to the squad will put him in the shop window for a summer transfer
"At the moment, I have left Derby and I am just looking for a club now. My agent is on to it and I think I have got a few clubs interested in me.
"But I have just got to concentrate on things out here now and put that to the back of my mind, and hopefully it will sort itself out when I get back," concluded the 29-year-old.