Those whom cricket's gods wish to diminish they permit to take a five-wicket haul when a 17-year-old debutant. Let us passionately hope it is not so with Sam Curran who has burst like a late-summer meteor on the English season.

While still a pupil at Wellington College, Curran dismissed eight Kent batsmen in his first appearance for Surrey at the beginning of the summer holidays and has since kept his place in the County Championship side. Before the current match against Lancashire he had taken a dozen wickets in Division Two and after the first innings he had 17. His 5 for 67 in the first innings of the game at Old Trafford was a career-best return, although "career" seems a rather elevated term for two months' cricket.

On Saturday Sam will play in the Royal London One-Day Cup Final against Gloucestershire. He will do so alongside his elder brother, Tom, a relative veteran with 21 first-class matches on his CV at the age of 20. Alec Stewart, Surrey's director of cricket, says that their places on the team sheet are "inked in". Yet so rapid has been the brothers' rise that plenty of people are not entirely sure who they are or exactly what they do.

"We need to talk to the Currans," request the media, eager to bring enlightenment. "The Currans"; it already sounds like a soap opera. Thankfully, the reality is more interesting, more exciting and vastly more promising.

Both the Currans will soon be qualified to play international cricket. Sam was born in Northampton in any case and Tom, although, born in Cape Town, will qualify by residence this October.

Tom Curran is a 6ft tall, right-arm seamer for whom 2015 has been a breakthrough season. He has so far taken 63 County Championship wickets and the emergence of his kid brother must not obscure Tom's importance to Surrey's attack. Bowling with a strong, high action and extracting plenty of nip from a rather unresponsive Old Trafford wicket this week, he had Alviro Petersen leg before with a ball with came back a little of the pitch and he then took the vital wicket of Ashwell Prince, who edged him to slip early on the third morning.

The ball which removed Prince moved away a shade and it highlighted Tom Curran's ability to give batsmen little peace and few opportunities to score runs. Surrey's scorecards this summer show him frequently going for around two runs an over while picking up vital wickets.

Sam is shorter and slighter. He is a left-arm swing bowler who has that fast arm which invariably embarrasses even the most experienced of batsman. He still has the look of a schoolboy about him and has to sweep an unruly forelock away from his eyes after almost every delivery. He scurries to the crease whereas his brother lopes in. But the contrast between the pair only increases their effectiveness, although Sam may eventually be a six-footer too.

Alec Stewart, Surrey's director of cricket, has guided the county back to Division One of the Championship Clint Hughes / © Getty Images

In time, one imagines, Sam will get even quicker, although his current pace was quite enough for Haseeb Hameed, Karl Brown and Steven Croft among Lancashire's top order. The first two were leg before to rapid inswingers whereas Croft was done by one which kept its line. The youger Curran has all the toys and he is learning very quickly how to play with them. Some at Old Trafford were making comparisons with the great left-arm seamers.

"Sam is the best 17-year-old cricketer that I have seen," said Stewart, the simplicity of the statement merely enhancing its impact. "You think that Chris Jordan or Graham Thorpe were good but the way he has taken to first-class cricket has been incredible."

The Currans can cope with the pressure, too, a facility illustrated, in Tom's case, by his coolness when bowling the final over of the Royal London semi-final against Nottinghamshire. Yet in that same game Sam dismissed Riki Wessels and Brendan Taylor with fast swinging deliveries, bowled with that distinctively whippy left-arm action which has had the coaches gazing in quiet admiration. The fact that it was a semi-final did not worry him either.

"A lot of players, young or old, almost shrivel in pressure situations in front of a big crowd," said Stewart. "Tom and Sam actually step up and they've enjoyed it. They haven't looked fazed at all. Whether it's been a first-class debut or playing in front of 20,000 people at The Oval, they've taken to it as though they've been playing in the local park."

Tom's wonderful array of abilities would, one might have thought, have earned him a place on a Lions' tour this winter. But he has been overlooked, with the selectors wary of selecting anybody who is not already qualified to play for England at this juncture, a fact which has left Stewart less than impressed.

"Tom has had an excellent season in white- and red-ball cricket and I am bitterly disappointed that his efforts and skills have not been recognised with a Lions tour," he said. "I find it staggering that he isn't in the squad because if he's not going to be an international cricketer, then my judgement of what makes an international cricketer is not what I think it should be."

"In one-day cricket he's bowled up front with the new ball, he's bowled at the death and he's bowled difficult overs. I'd just like to know why he hasn't been selected. He has that potential to be a future England cricketer and I believe that picking future England cricketers are what Lions tours are about."

Stewart's praise is reassuringly hard to win and he also believes that both the Currans will eventually bat higher up the order than they do now: Tom at around No7, Sam in a Ben Stokes role at No 5 or 6.

Stewart also knows that he has rare talents on his hands and he is understandably concerned to protect them from too much media attention. He remains forever grateful to Ian Greig, the former Surrey skipper who first tipped him off as to Tom's talent when he saw him playing in South Africa.

Sam Curran in action for Surrey in the Division Two title decider against Lancashire Clint Hughes / © Getty Images

"For players so young their cricket brains, nous and knowhow is so great that you would think they were 25, 26, 27," he said. "You just watch how they bowl and they have that sixth sense of what to bowl that normally you see in more mature cricketers."

And on Saturday morning the pair will trot out at Lord's to warm up before a large crowd. If Stewart is right, it will not be the last time they play on such occasions. They will, however, take it all in their contrasting strides. And as Sam, who remains a schoolboy, might point out, a Lord's final sure beats the hell out of Saturday morning lessons at Wellington.