London: Nick Kyrgios is three years away from winning a Grand Slam and the latest in an illustrious line of tennis 'bad boys' bound for greatness, said former Wimbledon champion Jan Kodes.

The Czech said Jimmy Connors, John McEnroe, Ilie Nastase and Roger Federer were also a whole load of trouble at the same age -- yet they matured and won a slew of majors.