Two Kerr brothers entered 2019 with high hopes of showcasing their talents on the global stage. One’s ambitions fell by the wayside, but the other has reached the desired destination.

However, Josh Kerr reveals it is the healthy rivalry with his elder sibling Jake that sowed the competitive seeds for winning his place, tonight, in a world championship final.

The 21-year-old is one of a tartan trio in the showdown for 1500 metres gold in Doha, joined on the start line by fellow Scots Jake Wightman and Neil Gourley.

Jake was a decent runner as a youth too, but rugby won the race for his affections. Now a hooker at Leicester Tigers, he earned his Scotland debut in the Six Nations last spring but he was left out of the squad which Gregor Townsend picked for the World Cup for Japan.

One up there, grins Josh.

“It’s a low-key competition, ” he says. “We keep messaging each other. But he’s been incredibly successful and working unbelievably hard. It’s such motivation to be part of a family that’s so hard-working. And to know we’re getting results from that.”

He could have traded lives too. At his school in Edinburgh, Adam Hastings – son of Gavin, and now part of the first father-and-son pair to feature in a Rugby World Cup – was in his brother’s year.

“But I played age group stuff with him when I was younger,” Josh recalls. “A bunch of people from school have gone professional either in sevens at Edinburgh or Glasgow.”

Despite the arduous training which Kerr undertakes in his twin bases in the mountains of New Mexico and at the HQ of his Brooks Beasts team in Seattle, a non-contact sport seemed easily the more favourable option.

“My physicality level was just not there,” he laughs. “But I do joke to my brother that I’d be easily be able to clean up because you just need to be able to catch a ball and not get caught.

“But I have a lot of respect for the sport. Those guys are very well trained and very well skilled. And the amount of time they spend the gym – I would just go crazy to be honest.”

Josh will require muscle in this evening’s shake-up on the track. Kenya’s Timothy Cheruiyot is the outstanding favourite for gold. But behind him, two medals are surely up for grabs.

“Anything can happen,” says Gourley, in his first major final.

“It could be a crazy race,” adds Wightman.

Josh is a 100-1 shot for victory. Astonishing odds, given his body of work and his pedigree in winning big races during his reign as the USA’s collegiate champion. On the international stage, he has still to make his reputation. He knows this is a big chance.

“I was No.1 in Europe at the start of the summer,” he said. “I don’t feel like I’m not a big name going in. I’m happy that I’m under the radar. You have got the big names, for sure. I haven’t raced Diamond League because I prefer to under-race. But there’s a bunch of people who might not be at their best because they’re burnt out.”

Big brother will roar him onward, to elude the pack and be the first one crossing the line.

“He’s rooting for me all the way,” Josh says. “He’s annoyingly good at cracking down on my races and telling me what I’ve done wrong. And what I need to work on. Along with my mum and my dad, they all know what they’re talking about. That’s helped me along.”