Ashley Giles says his attempts to become fit for the tour of India left him 'knackered' but vowed to join his England team-mates on the sub-continent if possible.
The 32-year-old Warwickshire orthodox left-arm spin bowler was on Tuesday ruled out of joining his team-mates on the flight to Mumbai on Sunday, having failed to recover from hip surgery as quickly as hoped.
England's premier spin bowler underwent surgery on December 7 in a bid to be fit for the nine-week tour but could not meet the time schedule to regain fitness.
"England need a fit Ashley Giles rather than a 60 per cent-fit Ashley Giles to bowl for them," said Giles, who has been replaced in the 16-man party by Somerset's Ian Blackwell.
"We have done everything in our powers. Quite honestly I am knackered.
"We have been working every hour we have been sent to get me on that plane. Maybe we pushed too soon? Who knows?"
Giles' recovery was interrupted after reacting badly to five and ten-minute workouts on the gym treadmill.
"We tried to run a couple of weeks ago and the hip didn't like it," he said. "The body has a way of telling you it is not ready.
"We knew then we were struggling. The timeline was quite fine, originally they said three months but perhaps quicker if everything went swimmingly."
That hopeful estimate was not aided by the damage in the joint - which curtailed his participation in Pakistan after two Tests - being worse than originally diagnosed.
Giles underwent a course of microfracturing, whereby holes are drilled to encourage new cartilage to grow. He said: "Basically we thought that the problem was just a bit of tear in the cartilage, a bit of an MOT repair and a bit of a clear-out. But when the surgeon went in there was more there than we expected, there was a bit of arthritis."
With repercussions from over-eagerness extremely serious, Giles is therefore taking a precautionary view on returning to action.
"That process actually takes quite a while; if you push it too quickly you can go backwards," he added. "In ten years' time, I certainly don't want to be in theatre having a hip replacement. That is the worst-case scenario.
"At least now I am not going to India on Sunday we can structure this a little bit better to get me running again at the right time and not push too soon. It is a very difficult balance to strike: when do I run? When I do bowl?
"We just need to be a bit careful now and the door is still open for me to go on the tour at some point.
"I am confident that, having had injuries before, once I can start moving properly and bowling I can be fit pretty sharply.
"So if I get to a point where I am pain-free I might be able to move very quickly. I am desperate to play for England but it is better if I am fit, looking at the long-term schedule for the next year or so and for my personal health in the years beyond that."
England were keen for Giles to prove his fitness because of the control he exerts in quiet periods. Despite averaging only two wickets per Test in his last 14, his batting strengthens the lower order and he has a safe pair of hands in the gully. Without him, the spinners are Shaun Udal (three wickets in three Tests at 92.33 apiece) and Monty Panesar and Ian Blackwell, both yet to make their Test debut.
"It will be tough for them," Giles said. "Although the wickets turn you bowl a lot of overs and India are exceptional players of spin, particularly on pitches they have been brought up on. As well as that they are close to being the best batting side in the world."