Scotland manager Craig Levein was looking in to Hooper's family history to see if the 23-year old was eligible for the national team and believed there was an opening when he discovered the player's grandfather was brought up in the Scottish Borders.
But it has since been revealed that Hooper's grandfather, William, was actually born in English border town Berwick, making the former Scunthorpe United man only available for England selection.
And after Stuart Pearce picked him in his squad for friendlies with Denmark and Iceland later this month as preparation for the summer's European Championships, Hooper insisted that international football was not on his mind when he first arrived at Parkhead in July last year.
"I wasn't thinking about playing international football when I came to Scotland," he told the Herald Scotland.
"I was just coming up to play for Celtic. Playing for England is a bonus. It's great to be called up and I'm looking forward to it.
"It was a surprise for me, in a way, what with me coming up from non-league football. It's my dream to play for England and now I'm in the 31-man squad. Celtic have helped me do that. I thought I'd come up here and take a year to settle down and find my feet, I didn't think it would come this early. But I'm very happy."
And Hooper revealed that he does feel fully English after being brought up in Essex.
"I went to a couple of England games when I was a kid and I've watched others on the telly," he added.
"The England strikers I admired were the likes of (Alan) Shearer, (Michael) Owen, Teddy (Sheringham). But now I've got a call-up. I'm very happy. I do feel 100% English because I was brought up in Loughton, Essex."