You know a sportsman has been in the wars when he beeps as he walks through security control at the airport.
"When I went to Borneo, they didn't even care," Mike McFarlane said of the alarm-inducing steel rod he has inside his leg as a splint for his broken shin.
"But going through Heathrow, there were about four people checking me. I had to say, 'Easy, easy'. I had to roll up my jeans and show them the scar."
The Abu Dhabi Harlequins back can laugh now about the fact he needs a doctor's note to confirm he is not a threat to national security but an injured rugby player.
But his ordeal over the past five months has been in turns gory and soul-destroying.
Back in May, McFarlane had been whiling away the final weeks of a triumphant first season in the UAE by trying his hand at rugby league.
In the last of a series of Emirate of Origin matches between Abu Dhabi and Dubai, the shoulder of an opposition tackler went through his lower leg and snapped his shin in two places.
His immediate train of thought as he lay prone and in searing pain were, in reverse order, as follows: will I ever play rugby again?; that trek we had planned for mum's birthday is not looking so good now; and, ouch. Overridingly, ouch.
"It was like two gunshots," said McFarlane, who has made his name as a tough-tackling enforcer in the Harlequins backline. "I've never felt pain like it, and I don't think I ever will.
"I had friends over on the other side of the field who were watching, and they said it literally sounded like gunshots."
The initial prognosis was that his rugby career was over. And this for a 26 year old who has designs on playing international rugby for the United States.
On the form he showed in his maiden season of domestic rugby, he would at least be a candidate for a place in the UAE national team if he were eligible.
"I had to have emergency surgery and when I got through it all I asked them if I'd be able to play again," the England-born centre said. "They were cotton-woolish, saying, 'Oh, we'll see, we'll see'. I was wondering if they were lying to me at that point.
"Once I'd got through that I then went to the outpatient appointment, the doctor said I would never be able to play again. That was a complete shock."
After surgery that involved dislocating his knee, drilling a rod into his fibula and bolting it in place at the knee and ankle, his initial healing was remarkably swift.
Upon examination of X-rays six weeks later, a specialist in the UK told him there was still hope.
It is still not guaranteed he will return to the field, but his recovery so far - he has been able to swim a kilometre per day of late - has been promising. He ditched his crutches a month ahead of schedule, just in time to start his new job teaching at Al Muna Primary at the start of the new school term.
"I thought it would be [career-ending] at the time, I think a lot of people did, but he has been defying all medical logic," said Chris Davies, the Harlequins director of rugby.
Tomorrow, Quins will begin their pursuit of the one major title to elude them last season, the UAE Premiership, with arguably the most talented backline ever assembled in club rugby on these shores.
Ed Lewsey is back to supply the ammunition at scrum-half, having played Championship rugby in England in the closing weeks of last season.
Jeremy Manning has been recruited direct from the professional game, having played in the English Premiership for the Newcastle Falcons.
Beside them there are the UAE international trio of Pat Hegarty, the fit-again Murray Strang, and Imad Reyal, newly-signed from Dubai Exiles.
And yet for all the talent, McFarlane, the flanker-turned-centre who was the pillar of the Quins midfield last season, is going to be conspicuous by his absence
"We are going to have some headaches when it comes to selection with the players we have, but there will be a notable difference with Mike not being around," Davies said. "He is such a strong, competitive character. He is a real winner which probably shows by the way things are going so well with his rehab."
While he may be winning the battle physiologically, the psychology of the comeback trail still weighs heavy on McFarlane.
Being bed-ridden staring at the ceiling for the first month was "horrendous" for someone so active. Then there is the anguish of not being able to join in with everyone else.
"It is killing me," he said. "All the lads are saying I should come up to the club and I think, 'Yeah? And what - watch you train?'
"I love those guys. I want to be involved in the club. I went to the senior players' meeting and it was really good. But it is absolutely killing me."
It is exactly that fear of being on the outside looking in which continues to fuel his recovery. He wants to be involved playing again before the end of this season.
He does not want to miss out on anything, which is why this summer's big family holiday to Singapore, Bali and Borneo, trekking through the rainforests for his mother's birthday, went ahead as planned. "I still managed to go, and did absolutely everything," McFarlane said. "I was on crutches, but I just had to push through."
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