"I had agreed to join St Truidense and then my agent told me that Marseille, Ghent and Standard Liege were all showing interest. But I couldn't break my word.
"Maybe it's sometimes worked against me but I was always taught that, if I was honest, I would go further in the game."
Boffin is famous for his non-stop performances. So if he's planning to play until he is almost 40, what is his secret?
"Ever since I was 20, I've slept for about two hours after training. I drink two to three litres of water a day and I eat five or six bananas, for my muscles.
"I don't smoke and I don't drink. I don't like champagne or wine. Maybe I'll have a beer with the family or with players but that's about it."
Then Boffin paused. "On reflection, though, the real secret is lots of luck."
He has played 48 times for Belgium. Surprisingly, he's only scored one goal - against Colombia in 1997.
His father and uncle were professional footballers and, if selected, this will be Boffin's third World Cup, after trips to the USA and France.
Asked to discuss key players, Boffin prefers to talk about the team. "We don't have superstars, there's no Beckham or Owen. We all need each other," he said.