Norwich City defender Zak Whitbread has withdrawn from the USA squad due to a back injury picked up in Saturday's 1-1 draw with Hull City.

The 27-year-old was called up for their forthcoming games with Argentina and Paraguay on March 26 and 29 respectively - his first inclusion in the senior national side, having made five appearances for the United States Under-20s whilst a youngster at Liverpool.

Whitbread has only recently cemented his place in the starting line-up after a year interrupted by a series of injuries.

Whitbread admitted earlier this season a full international call up was a long-term ambition after featuring for the US at younger levels.

'The first priority was to get back (healthy) and to get back playing and doing well for Norwich,' he said. 'I've always said anything beyond that would be a massive bonus.

'It's still something that's high up there on the list of ambitions, which I would like to achieve. I've played in the U20s and U23s, so it's something I've really wanted to do. As I said, all I can do is keep performing as well as I can for Norwich and hopefully the national team is aware of me and hopefully I'll get a chance sooner or later of proving what I can have to offer.'