Speed is a key attribute in any defender’s game. It can aid recovery against the quickest of attacking opponents, provide a useful tool when possession turns over quickly in midfield and offer a menacing threat going forward.

It is also one of the most difficult skills to teach, according to Adam Gemili, who spent eight years as a pacey full-back in the Chelsea Academy before swapping the football field for the athletics track.

‘I was a defender, centre-back or right-back, and always played as the last man because nobody was going to get past me,’ the sprinter revealed to the official Chelsea website.

‘I was noticeably the quickest in the Academy and having speed really helps you in football, as long as you have a good touch, can pass and tackle, get stuck in and give it some heart. Speed is much harder to teach so it was always something the coaches utilised in my game.’

Read - Adam Gemili on bus rides into Cobham with Loftus-Cheek to world athletics gold

Gemili ultimately made the decision to walk away from football and utilise his blistering speed in a different career. He left Chelsea at the age of 15 and had spells at Reading and Dagenham & Redbridge before taking up athletics permanently.

‘I was dabbling in athletics a little, not a huge amount, but I ended up taking the decision in January 2012 to completely walk away from football and pursue athletics full-time,’ he explained.

‘I started training with a coach in north London and was so fortunate with how quickly I picked it up. I just started running fast and ended up making the Olympic team in 2012 after training for seven or eight months.’

He narrowly missed out on the 100m final at London 2012, finishing third in his semi-final, an agonising 0.04 seconds off the qualifying pace. Switching sports comes with particular challenges and Gemili admits that going it alone proved the most difficult aspect of his career change. Gone were the days of sharing digs, dressing rooms and camaraderie with his footballing friends, replaced by the sudden realisation that success or failure in a sport of such fine margins was all now down to him.

‘One of the hardest things to adapt to was going from a team-based sport to an individual sport,’ Gemili continued. ‘You go from being in the changing room with team-mates, living and training with them every day, to a situation where if you don’t get on the line and run then nobody else is going to run for you.

‘In football, you can sometimes get away with an off-day but now there’s nobody else to put the work in if you don’t.’

However, when reflecting on one of his biggest achievements on the track so far, the 4x100m relay triumph in London two years ago, it is his understanding of working as part of a team that he credits as key to the success.

‘The experience of being part of a football team is what really helps me with relay,’ he continued. ‘I can bring the team together and I know how strong a well-bonded team can be. It doesn’t matter if you’re not the most talented because if you have that teamwork, it trumps everything.

‘When we won the gold medal in London [at the 2017 World Championships], we weren’t the four quickest guys but we were the strongest team so we ended up winning gold in our home championships. I credit some of that to my football background and bringing that strength of a team to track and field.’

At the 2019 World Athletics Championships, which are underway in Doha, Gemili will defend his world relay title as well as break new ground for a British sprinter.

‘I can’t wait - the World Championships is what we train for all year and I’ve been training well, running fast and my body is good so I’m going out there to do my best,’ he said. ‘It’s the first time any Brit has attempted to double up and run both the 100m and 200m so it’s an exciting event for me.

‘Hopefully I can pick up a few medals, have a good championships and it will set me up nicely for the Olympics next year in Tokyo, which is the big one.’

As he prepares for the sound of the starting gun on the white line in Qatar, Gemili may well reflect on his journey to the top of British athletics. In fact, it was at a recent running event in Northern Ireland when the 25-year-old allowed himself a brief moment to take in his unique pathway from footballer to foot runner.

‘I was thinking the other day about how everything has worked out and how nuts it is that I’m competing in a completely different sport now,’ admitted the sprint star. ‘I had a race a few weeks ago in Belfast and the last time I was there was at the Milk Cup playing for Chelsea.

‘Dreams change and you have to be realistic. It’s just crazy how life can completely change but I’m so happy I found myself in another sport.’

-Gemili runs tonight (Tuesday) in the 200m final at the World Athletics Championships in Qatar.