Tymal Mills is one of the most explosive fast bowlers in English cricket, capable of speeds comfortably in excess of 90mph, but his career reached a watershed in 2015 when he was diagnosed with a congenital back condition: his spinal cord and vertebrae are unusually close together and bowling fast too often can agitate his spinal cord. It threatens to consign him to a future as a white-ball bowler, and he has to tailor his training carefully even to cope with that but with Twenty20 growing in importance neither Mills nor Sussex - nor even England - have abandoned hope that he can make an impact. England awarded him a T20I debut against Sri Lanka at the Ageas Bowl in 2016.

Mills only started playing cricket when he was 14 - and it was another two years before it became a serious part of his life - but by the age of 19 had forced his way into the Essex first team, abandoning a journalism cause at the University of East London in the process. He progressed through the academy set-up at Essex and represented England Under-19s and his Championship debut came midway through the 2011 season. By then the National Academy scouts had taken notice and that winter he was fast-tracked on to the Performance Programme, before playing for the Lions on their tour of Bangladesh.

Mills' workload was carefully managed, but he attracted considerable hype: before turning 20, he topped 90mph in front of the Sky TV cameras; then, with Mitchell Johnson terrorising England during the 2013-14 Ashes, there were calls for Mills to be fast-tracked to the Test side to provide similar firepower (he had been used for practise against left-arm bowling in the nets and almost put Graeme Swann out of the tour when her struck him on the arm). A record of six Championship wickets at 66.33 in the 2013 season counted against him and, even though development continued with the Lions in Sri Lanka, he left Essex at the end of another mediocre season in 2014 to join Sussex in the hope that it would galvanise his career so that the statistics began to meet England's hopes. Then came the revelation that his future would be in short-form cricket, a diagnosis that he learned to handle with equanimity - even more so when three stand-out T20 performances for England against India led to Royal Challengers Bangalore recruiting him for £1.4m in the 2017 auction.

ESPNcricinfo staff