As Josh Hull prepared for his England debut, much of the talk centred on the enormity of his feet and first-class bowling average.

The 20-year-old left-arm seamer with size 15 boots had taken his 16 red-ball wickets for Leicestershire at an unremarkable 62.75. In Division Two of this season’s County Championship, he had struck twice in three matches at an uninspiring 182.50.

But England care little for these sorts of statistics when it comes to choosing bowlers. They pick on potential. Josh Tongue’s selection proved that. So did the inclusions of spinners Tom Hartley and Shoaib Bashir. Hull now the same.

“County cricket and Test cricket are probably slightly different games,” said head coach Brendon McCullum when discussing Hull’s selection for the third and final Test against Sri Lanka.

“If we were putting together a county side it would look a little bit different to what it looks in the Test side.

“What we are trying to achieve is bringing in guys we see as rough diamonds with an incredibly high ceiling into an environment where we can shape them and give them opportunities, hasten the process of them getting to the level we think they can get to.”

It is early days but Hull showed in his opening burst at The Kia Oval, which included the wicket of Pathum Nissanka, that he is a “rough diamond” who may just glimmer for years to come

Broad: Hull run-up will evolve over time

The statistics of Hull’s England do pay attention to are his 6ft 7in frame – or 6ft heaps as McCullum described it ahead of the Test – and that he can bowl towards 90mph, key traits as they ultimately plot how to win the Ashes in Australia in a couple of winters’ time.

Hull reached 87mph during his five-over stint on Saturday but also moved the ball, leaving the Sky Sports pundits encouraged.

“I have been really impressed,” said Stuart Broad. “He has been picked on attributes. His height, his bounce, getting the ball to swing back into the right-handed batter.

“An average of 83mph is fine in Test match cricket but he will get quicker the older he gets. I think his run-up will evolve over time. I don’t think it will stay as long as it is at the moment.

“His knees go forward rather than up so he doesn’t have the dynamic approach that you might want, so maybe that’s why his run-up is so long.

“The big thing for me is that his feet and hips are facing the target – he is aligned really nicely to make the batters play.

“His front arm also moves nicely and he has a braced front leg so gets a good flow through his action. That’s where the best fast bowlers generally get their pace from.

“Ultimately his biggest strength is that he is left-arm. All teams are desperate to have that in their armoury.”

Could Hull use his height more?

Sky Sports Cricket’s Stuart Broad:

“He could. He reminds me slightly of Mitchell Johnson with that slingy action so he could get that bowling arm closer to the ear and deliver from higher.

“But you have to be able to do that and not lose the swing as that is a great threat of his.

“The slingy action might not be a negative. It might not allow you to get the bounce you would like but you can get the ball to skid on.”

Former Australia captain Ricky Ponting:

“I definitely like what I saw [but] I think there will be some refinement to his action over the years.

“His bowling action is so long that he loses a bit of his height. In this game, it is quite often bounce that gets better players out, not always express pace.”

Watch day three of the third and final Test between England and Sri Lanka, from The Kia Oval, live on Sky Sports Cricket and Sky Sports Main Event from 10.15am on Sunday (11am first ball).