Mark Wood, England's most explosive fast bowler, will get the first indication as to whether he can rebuild an injury-ravaged international career later this month when he bowls flat out for the first time since he was laid low by a third ankle operation in a year.
Wood goes to Potchefstroom in South Africa for an England fast bowling camp armed with a reshaped bowling action and a specially-designed bowling boot, as he looks to reaffirm that he can once again bowl with the extreme pace and penetration that England have at times lacked in his absence.
He admits, however, he had to suppress doubts about his future in the aftermath of his latest operation. "I had doubts in my head - would I ever be the same bowler," he said.
Simon Jones, who suffered injury hardship himself, but who fought back to be part of England's victorious 2005 Ashes-winning squad, was an influential voice, urging Wood not to give up when the pair met at a cricket dinner, and there was moral support too in a more recognisable north-eastern brogue from his former Durham and England team-mate Steve Harmison.
England were at times crying out for a bowler of Wood's hostility as they sunk to a 4-0 Test series defeat in India, not that he studied the series too closely. "I don't know anyone who finds it easy to watch when they are unfit. There were times when I did watch because I wanted to see how my friends were getting on, but if you could watch it when unfit and be happy, then you're not a competitive sportsman."
There was no more courageous act in cricket last year than Wood's determination to stay on the field for Durham during a vital Championship match against Surrey in September, when it was later discovered after the match, to general astonishment, that he had been bowling with a severed left ankle bone.
More than four months on from his latest bout of surgery, he is now back up to about 60% pace at the National Performance Centre, under the scrutiny of the ECB's lead fast bowling coach, Kevin Shine, with whom he has built a close and trusting relationship.
He is approaching the most crucial weeks of his career in philosophical manner. "Hopefully now my ankle has nothing left in it, so that should be fine," he said.
Shine knows all about the anguish that repeated ankle problems can cause for a fast bowler - he was briefly regarded as the fastest bowler in county cricket a generation ago, but was hampered by three operations - and he has nothing but admiration for the determined manner in which Wood is trying to revive his England ambitions.
Wood is undergoing adjustments to his bowling action, rather than any attempts at a full-scale rebuilding, to seek to reduce the impact on his left ankle without undermining the explosive power that has seen him regularly hit speeds in excess of 90mph.
"People have said you need to change your action but, if I change my action, I will just end up with a bad knee or a bad back," he said. "I have one bad joint because of the way I splay out my front foot.
"Basically, my left hip and back foot are the two areas I am working on. I got a little bit crossed over during the season and that led to the problem with the broken ankle. I'm working on not coming across my front hip so much."
Wood's front foot will always point outwards at the point of delivery, but he is aiming to come over the top of his foot rather than the side.
"Last year I got in the habits of putting my game-time first and neglected the training side a little bit," he said. "I now need to get my action solid as a rock, like it was when I made my debut for England."
Tests at Loughborough have confirmed the immense stress that Wood puts on his body when he bowls. He only weighs 78kgs (a little over 12 stones) and he generally bowls with between 90-95mph intensity. "Some will bowl 80-85%, which is probably why injuries follow me a bit more regularly," he said.
For every delivery, his ankle must withstand the force of more than seven times his weight, which puts him slightly above average. He does not measure the highest on that test however - Matt Taylor, the Gloucestershire left-armer, returns statistics of x9.
His knee also hyper-extends towards the ground when he delivers, in the manner of Allan Donald, but while his ankle has repeatedly let him down, his knee has never given him a moment's concern.
It was Shine who first warned Wood that his action was deteriorating when he was bowling for England in an ODI against Pakistan in late August.
"I took three wickets and did OK but I remember watching it back and thinking my action looks horrible here and I texted Shiney on the night and said 'can you just have a look at it?'. He said it was a little bit of a mess, and we would have to have a look at it in the winter, but I didn't get that far."
The purity of his action might have been faltering but, in Twenty20, he bowled two of the most memorable spells of the season, blowing away Gloucestershire in the NatWest Blast quarter-final and then proving too much for Yorkshire on Finals Day at Edgbaston before Durham lost to Northants in the final.
It was the sort of impact performance that must have left the IPL and Big Bash drooling, but such ambitions are for later: there is no talk of having to become a T20 specialist if his body gives way once more. His focus is on getting back on the field for England in a Test for the first time since Pakistan in Dubai in September 2015.
"All I am interested in at the moment is when I can get back to play for England," he said. "I have had a little taste of it and think I can do better than I have shown. I still have a great inner belief and want to prove how good I can be."
By his first day in Potchefstroom on January 26, he anticipates he will be back on his full run for the first time and approaching full intensity, and Shine will be guiding him every step of the way.
"It's great to work through this with Kevin Shine. I trust him. You can name loads of great bowling coaches I've worked with but I've a great relationship with Kevin Shine. He can continue my progress. When I first got into England Lions he was my bowling coach and he knows everything about it. He knows when my bowling action was strong. "
Wood recognises that hindsight suggests he should never have played in Durham's Championship match against Surrey. Mindful of the stigma that so often attaches itself to injured sportsmen, he insisted upon playing. Foolhardy perhaps, but it is impressive to see county loyalties running so thickly.
"It is ingrained that you can't be soft. I didn't want to let anyone down and say that I had broken down again. I just tried to suck it up. Halfway through the game I realised there was something bad. But when I saw the result I couldn't believe it was that bad. The injury wasn't just like a fracture or a chip. I broke it clean off.
"If I had my time again, I maybe wouldn't have played that game but [then] I would have left Durham in the lurch or there would have been a fracture there anyway. At least I knew I tried my hardest to keep Durham in the league."
The irony is that is all proved to be pointless. Wood's post-operative state of mind was hardly enhanced when Andrew Strauss, England's managing director, rang him to advise that Durham, who had finished as high as fourth, had been relegated by the ECB as punishment for needing a financial bale-out.
"I am proud of where I come from - I love the north east. There was bitterness from the players' point of view. The players hadn't done a lot wrong. We had managed to stay up. I understand the ECB have to set a precedent so that this doesn't happen again but I couldn't believe how harsh it was."
Wood was assured by Strauss that playing for Durham in Division Two would not undermine his England chances.
"He said they had seen what I could do. I knew then I could stay where I want to stay. When I do play for Durham - and to be perfectly honest, I hope it isn't much because I want to be playing for England - I hope I can help them get back to where they belong."