Speaking on talkSPORT's Sports Breakfast, Flintoff admitted Neville could have been England's answer to Ricky Ponting or Sachin Tendulkar had he pursued the sport he, admittedly, first loved.
"He (Phil) was a year older than me and he was a cricketing genius," Flintoff said.
"This is a big call, but if he had carried on playing cricket he could have been England's Ricky Ponting or Sachin Tendulkar. He was that good.
"He used to turn up, open the batting and score a hundred every time he batted, and then he’d bowl everyone out.
"He was a quick bowler and he got offered a contract at Lancashire - I think £2,500 was the wage - or go play at United.
"Luckily he went to United otherwise I might have ended up at Derbyshire or something."
While Flintoff went on to become one of England's greatest ever players, Neville, alongside brother Gary, saw unprecedented success together at United, including six Premier League titles and the UEFA Champions League.
Gary, too, possessed prowess with the bat and ball, having once scored a century as a 17-year-old alongside Matthew Hayden in Bolton's Hamer Cup.
Though still an impressive feat, Flintoff assured it was no match for Phil's portfolio.
"Gary played as well and if you listen to Gary he was the best cricketer who ever walked the earth,” he joked.
"He’d have made a good club cricketer at Bolton, but Phil was the one who was amazing and such a good lad as well."
