The eighteen-year-old has been training with England Lions in the United Arab Emirates over the last three weeks and has done enough to persuade the management that he is ready join the senior side, despite having just three first-class appearances under his belt.
Ahmed only made his County Championship debut for Leicestershire in May and stands on the brink of full Test honours having bowled only 446 balls in first-class cricket, with nine wickets.
If he goes on to win selection in Rawalpindi, Multan or Karachi he will beat the previous record of Brian Close, who first wore the Three Lions at 18 years and 149 days in 1949.
But he has been tipped for big things from a tender age, earning media attention at just 11 when he dismissed Ben Stokes and Alastair Cook in the nets having been invited to bowl at the national team.
He was picked up in The Hundred by reigning champions Southern Brave earlier this summer despite a lack of competitive experience and was subsequently invited to train with England's white-ball team at Old Trafford, benefiting from a lengthy session alongside fellow leg-spinner Adil Rashid.
Ahmed had just finished playing for England Lions against the full England side on the opening day of a Test warm-up match in Abu Dhabi when the news was announced.
Figures of nought for 73 off eight overs were not exactly how he would have chosen his outing to go, but with a score of 501 for seven at the close of play it was clearly a batting day at the Tolerance Oval.
Crucially, he has showed the right kind of attitude in a set-up that values that above all else.
England Test coach Brendon McCullum said: "We know he's not the finished article and has raw potential, but Ben (Stokes), myself and the rest of the coaches like how he approaches his game.
"The experience of being part of the squad in Pakistan will be hugely beneficial for him, and he will add to the make-up of our squad."
England initially selected Jack Leach as the only specialist spin bowler, supplementing him with all-rounders Liam Livingstone and Will Jacks.
Matt Parkinson, who made his debut as a concussion substitute earlier this year, and Dom Bess were both overlooked and appear to have slid even further down the pecking order.
England squad for Test series in Pakistan: Ben Stokes, Rehan Ahmed, James Anderson, Harry Brook, Zak Crawley, Ben Duckett, Ben Foakes, Will Jacks, Keaton Jennings, Jack Leach, Liam Livingstone, Jamie Overton, Ollie Pope, Ollie Robinson, Joe Root, Mark Wood