But he is just relieved to have a second chance after the horse, trained in the Scottish Borders by his father Stuart, finally made the 40-runner cut for Saturday’s showpiece race.
Even though Coltherd junior was always hopeful – he is a born optimist – it became too close to call after Gordon Elliott, Ireland’s leading trainer, signalled that he would saddle as many as 13 runners in the marathon.
The relief was self-evident when The Yorkshire Post informed the young jockey on Monday afternoon that the handicap ratings had been revised and Captain Redbeard, 41st on the list, had swapped places with Elliott’s Bless The Wings in the wake of a win at Kelso last month over Gold Cup contender Definitly Red.
“I called Dad and he was shocked,” said Coltherd. “He repeated himself a few times on the phone just to make sure that he had heard me right. It’s a relief that we know now so we can plan for the week ahead.”
For Coltherd’s father, who also owns the steeplechaser, it means overseeing the final preparations of Captain Redbeard while tending to his flock of sheep, and new-born lambs, on the family’s farm.
For his mother Lesley it involves coming to terms with her big-race nerves – she is more than likely to stay at home on Saturday and try to watch a race worth £1m on TV from behind the living room settee.
For his sister Amy, who looks after the family’s horse of a lifetime, it means making sure that Captain Redbeard looks the picture of health when he parades on Merseyside.
For Coltherd, who is a conditional jockey at the Bingley stables of Sue and Harvey Smith, who won the 2013 National with Auroras Encore, it is a chance to learn from last year’s race.
He and Captain Redbeard were travelling well when they had to take evasive action at the world-famous Becher’s Brook to avoid the Smith-trained I Just Know, who had crumpled on landing under Danny Cook.
But it meant Captain Redbeard was left on the outer for the short run to the seventh, the smallest fence on the course, which is taken on an angle.
It saw the horse jink slightly and Coltherd hit the turf soon after in a mistake emblematic of the contest.
“You can win and lose the National on the first circuit – and I lost,” said the 20-year-old, who will be one of the youngest riders in this year’s line-up.
“Very frustrating. I have watched the replay several times throughout the year, not just this week. Jeez, it was just a very silly mistake – the horse has jumped round there fine every other time. I had to go round Danny at Becher’s and was stuck wide. He (Captain Redbeard) has twisted mid-air and I went out the side door.
“A bit of jockey error and a bit of losing my position. A split-second decision, small margins.”
It is not lost on Coltherd, now on the 10-winner mark for the campaign, that he was in close proximity to Tiger Roll, who went on to win the race from Pleasant Company in a pulsating finish – one horse’s stroke of luck can be another runner’s misfortune.
Last year’s first and second will renew their rivalry with Tiger Roll attempting to become the first dual winner since Red Rum in the Seventies.
While they are proven stayers, the remainder do have stamina doubts, says Coltherd.
“The way Captain Redbeard worked on Saturday, he has the spark from the days when he won good races at Haydock,” added the jockey.
“We know how the week, and the day itself, will unfold. I’m fortunate – I’m still only 20 and riding in a second National.
“I’m not saying it is going to be easy. If we can get round the first circuit we can ride the race – we just need a wee bit of luck on our side.”