Rio Ferdinand singled out three former Manchester United players who are part of a legendary WhatsApp chat featuring ex-footballers from the Premier League club’s past. The Manchester United defender enjoyed a prolific career at Old Trafford and experienced incredible success under legendary former manager Sir Alex Ferguson. Rio Ferdinand lifted six Premier League titles, a Champions League and two League Cups during his time at United before his exit from Old Trafford in 2014. The 45-year-old TNT Sports pundit was a key part of Sir Alex Ferguson’s United teams of the past, having forged a for…