Max Lamb, now 11, had to have the operation to remove his right leg after an amniotic band cut off his blood flow in the womb.
But now his family are delighted after he has joined the England Amputee Junior Football squad.
Dad Chris, 46, who lives with wife Rachel, 40, in St Helens, Merseyside, said: “Max is absolutely loving playing football – all the players have been so welcoming.
“He’s made some amazing friends, and playing football has given him a real purpose.”
READ MORE: Public urged to check for strange symptoms as new Covid variant threatens return of masks
The couple, who also have a daughter Niamh, seven, were told about Max’s condition when Rachel was 20 weeks pregnant.
Loose bands of tissue in Rachel’s womb had become wrapped around Max’s right leg, preventing it from developing normally.
A spokeswoman for Limb Power, a charity which supports amputees and their families, said Max was the youngest amputee they had heard of in the country.
Civil servant Chris said: “When Max had to go down to the operating theatre he was so tiny at just a few weeks old. It was incredibly worrying. But he came up from the operation smiling and it was such a relief that everything had gone smoothly.
“Because he had his amputation at such a young age, it meant he didn’t have any phantom pain where the missing limb should be, which can sometimes happen for amputees.
“He also has one hand smaller than the other and his remaining toes didn’t form properly, but he has never let that hold him back. He always has a smile for everyone.
“He copes remarkably well. He used to tell his classmates when he first started school that his leg had been bitten off by a shark.”
Max had a prosthetic leg fitted when he was nine months old.
Chris added: “The leg bone has carried on growing so he’s had to have surgery intermittently to shave it down and to have a metal plate fitted too. So he’s spent a lot of time on crutches over the years.”
All the amputees play on crutches, without their prosthetic legs, apart from the goalkeeper. Max plays in midfield.
Organiser Elaine Oakey said: “Max always puts 100 per cent effort in and is a valuable team player.”
Junior head coach Harry Smith said: “Many of these junior players will go on to compete internationally. Our adult team competes all over the world and we train the junior squad in preparation for the international squad after they have reached the age of 18.The skill level is really high.”