Jermaine Jenas has admitted that Sir Bobby Robson's sacking from Newcastle United in 2004 may have prevented him from reaching his potential.
The 31-year-old arguably signalled the end of his injury-prone playing career by joining the BBC as a football pundit on a two-year contract on Friday.
Jenas broke into the England team during his time at St James' Park under Robson, and while he does not feel that he underachieved, he concedes that he may have reached greater heights had he had the benefit of the legendary manager's guidance for longer.
He told BBC Sport: "I'm more than happy with what I've achieved in my playing career, but I understand that at the start of my career it was a bit of a whirlwind and people were asking '"what is this kid going to go on and achieve?
"Losing Bobby Robson, for me, was bigger than people think. He really understood me as a player - when I needed a rest, when I needed to go back home or when to play me, when not to play me and how to play me.
"He had the exact formula for what I needed to go on and develop as a player and it was kind of going back to square one in my mind [when he left]. It shook me a little and I took the chance to go to Spurs."
Jenas, who won 21 caps for England, left Newcastle to join Tottenham Hotspur in 2005. He started his career at Nottingham Forest and also played for Aston Villa and Queens Park Rangers.