England fast bowler Mark Wood has revealed a simple footwear malfunction is to blame for his latest spell on the sidelines due to injury.
The Durham quick hasn't played since the second Test against South Africa a month ago when he was ruled out due to a bruised left heel and he says some worn insoles in his bowling shoes led to the injury.
"It was my own stupid fault, really," he told BBC Five Live.
"I put the wrong insoles in my shoes at Lord's (in the first Test) and bruised my heel and then played the second game with a bruised heel and ended up not doing myself justice.
"I had some new boots just to freshen things up and I ended up putting some of the old (insoles) in and they were a bit broken and didn't quite have the same padding. Unfortunately, that meant when I was landing on the corner of my heel, it bruised it.
"It sounds like nothing but when you're putting a lot of force through your front foot it obviously can get a bit painful."
The career of Wood, regarded as one of the fastest bowlers in the England set-up, has been hit hard by injuries in recent years.
The right-armer has managed just 10 Tests since his debut in 2015 and last year had surgery on his left ankle for the third time in his career.
The Durham quick's trademark, apart from speeds that can exceed 150km/hr, is an unusually short run-up of no more than nine strides.
Wood says he's spoken to current England bowling coach Ottis Gibson and former fast bowler Simon Jones, who himself was hit hard by injury during his career, about possibly lengthening his approach to the wicket in order to prevent further injury.
But he says those discussions have not yet resulted in a definitive answer.
"A lot of people are speaking about my run up and ... I hear a lot of things about is it too much stress on my body and ultimately giving me these injuries," he said.
"I asked (Gibson) if he thinks if I lengthened my run up, would it put less stress on my body? Because that's the big question over my career at the minute, it's always about injuries.
"You still want to be flying in and bowling fast so I don't want to be changing anything like that."
Wood is pushing to return to full fitness in order to win selection for what would be his first Ashes tour this summer.
But with Jimmy Anderson and Stuart Broad certain to tour and Chris Woakes as well as Toby Roland-Jones also in the frame, competition is fierce for fast-bowling spots in the touring party.
"Things are a lot slower than I hoped," the 27-year-old said of his rehabilitation.
"Obviously with a bruised heel, I've had this injury before and it takes a long time. You think you’re getting better quickly but as soon as you bowl you're back to square one. So I have to do all the fitness things.
"It's just really annoying and frustrating, to be honest."
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