England spinner Graeme Swann fears his troublesome elbow injury could cost him a chance to face Australia in the Ashes as captain Alastair Cook said keeping their top players fit will be crucial in a huge year of Test cricket.

The first of 15 Tests in 2013, which culminate in back-to-back Ashes series against Australia, will begin on a comparatively quiet note when the world No.2-ranked English face lowly New Zealand in Dunedin on Wednesday in the first of three Tests.

Both nations will square off in two further Tests in England in May, leading into the Champions Trophy one-day tournament in that country.

But for the cricket purist, the cricketing year truly begins in July-August when holders England seek to defend the Ashes.

A return five-Test series in Australia from November to January turns it into a punishing year for Cook’s men but one the skipper hopes will be hugely rewarding.

England’s favouritism to retain the Ashes is firming by the day as Australia struggle on their tour of India.

That’s in contrast to England’s 2-1 series triumph in India before Christmas, although Cook didn’t want to talk up the comparison.

Cook said it would be naive to expect England can keep the same playing XI through the year.

“In an ideal world you would but we know how injury, particularly in the fast bowlers, plays a part,” he said.

“We are lucky in the strength and depth we have in that department and we can rotate players if we need to, or if someone gets injured then replace them with someone of similar ability or class. And I think that’s a very comforting place to be.”

Meanwhile, Swann said the right elbow he had surgery on in 2009 still causes him some discomfort.

“We are embarking on arguably England’s greatest year of Test cricket ever and I can’t wait for the back-to-back Ashes series. But I have one big worry – the state of my right elbow,” Swann wrote in his column in The Sun.

“I’ll be honest, the elbow is always a concern.

“It would be a massive pain in the backside if my wonky elbow forced me to miss any of the Tests against Australia. I’m absolutely determined to be available for what might be my final two Ashes series – and that means managing the elbow as well as possible.”