Here, the PA news agency delves into the life of the Wasps flanker.
Humble despite honours
A brilliant season at Wasps earned him recognition as the Gallagher Premiership player of the year and Rugby Players' Association player of the year, but the 23-year-old is humble about winning the awards. "I've had them on my desk, I didn't want to keep them downstairs because it would look like I'm showing off," he said.
Make up the breakdown
Although a well-rounded player, it is his breakdown expertise that identifies a rare talent. In the 2019-20 season he plundered 46 turnovers – 27 more than his nearest rival Blair Cowan. A combination of strength over the ball and the flexibility to manoeuvre himself into awkward positions set him apart. The regular stretching sessions that started at an early age have paid huge dividends.
Next career move in the pipeline
During spells rehabilitating serious knee and ankle injuries, Willis came to the understanding that he needed to plan for life beyond rugby and so took up an evening plumbing course with his brother Tom at Warwickshire College Group. He expects to receive a diploma soon, but an NVQ is the ultimate aim.
Tough brotherly love keeps him going
A 13-year-old Willis temporarily fell out of love with the game after being rejected by London Irish, but his chance was to come alongside Tom at Wasps. Tom, also a flanker, is two years younger but the two started last month's Premiership final defeat by Exeter in the same back row. "Me and him are probably each other's harshest critics. Competitive brothers we are always pushing each other," Jack said.
Two years is a long time in rugby
But for two lengthy spells in the treatment room, Willis might have made his debut two years earlier. He was picked for the 2018 tour to South Africa only for a knee issue to force his withdrawal. Misfortune struck for a second time when just a few games into his comeback at Wasps he damaged his ankle. Restored to full fitness in time for this season, he has produced form that former England prop David Flatman believes identifies him as "the best player in the Premiership by a stretch."