The 25-year-old had barely started the new season when the coronavirus pandemic put a halt to proceedings and he found himself back on his family's farm in Haverfordwest earlier than anticipated, with his wait for a first Olympic appearance pushed back 12 months.
But while many of his fellow competitors have been unable to train consistently throughout the lockdown, Commonwealth Games silver medallist Llewellin has had no issue keeping himself on form, having constructed his own range shortly after his 18th birthday.
And with some extra time on his hands in recent weeks, Llewellin – who is one of more than 1,100 elite athletes on UK Sport's World Class Programme, funded by the National Lottery – has been getting his hands dirty once again as he looks to clinch success without a gun in his hand.
"My dad's always got a list of jobs to do longer than his arms," he said. "I'm a self-taught bricklayer and I'm a qualified carpenter, so I've been kept busy by being in charge of putting the house together for my older brother, Luke.
"It's been a strange year. I'd just completed my first World Cup of the year in Cyprus when the lockdown started. It had been a good start and I thought I was heading a successful year with the Olympics on the horizon, but then things changed.
"But I'm very lucky with the situation I'm in, being surrounded by my family and being able to train on the range. I'm still waiting for some dates to aim towards before I resume full training, but I've been able to keep ticking over when a lot of other people haven't.
"I've managed to keep my mind focused and positive and although I was extremely excited about the prospect of going to my first Olympics this year, in a way I've been given some extra time to make sure I'm in the best shape possible to go there and do well next summer."
Having picked up a medal in Australia in 2018, Llewellin is clear that he harbours ambitions of a podium place in Tokyo, and he is determined to put in the necessary groundwork to make his wish a reality.
With a high percentage of the world's population having being affected by the ongoing pandemic, the Welshman hopes the event will represent a coming together of all nations, and will be remembered as more than just a sporting event.
And as he continues his journey towards the pinnacle of his sport, he acknowledges how much he owes to National Lottery players, with 864 Olympic and Paralympic medals won since funding started in 1997.
He said: "It's always been a huge aspiration of mine to compete at an Olympic Games, and win an Olympic medal. I really can't put into words how much it would mean to me, but I do go to every competition to win and that'll be no different next year.
"I think there's the opportunity for it be an unbelievable occasion in Tokyo. I really hope it's able to go ahead as planned so that everyone can come together and enjoy the great event it promises to be.
"If I get there, the National Lottery will have played a big part in helping me do so. I don't think I would've been able to get as far as I have now – and as far as I want to go – without their support. I'm extremely grateful and equally determined to make the most of the opportunity I've got."
No one does more to support our Olympic and Paralympic athletes than National Lottery players, who raise around £30 million each week for good causes. Discover the positive impact playing the National Lottery has at #TNLAthletes #TracktoTokyo