Vignal joined the Reds in 2000 in a £500,000 move from Montpelier but made only a handful of first-team appearances as he struggled to displace John Arne Riise.
The 28-year-old, now available for selection again after a hamstring problem, wishes he had been more patient on Merseyside.
Vignal said: "I should have stayed longer at Liverpool and been patient but, when you are young sometimes you don't realise things.
"I only played a few games at Liverpool, and when you are young, you want to play every game. I should have said `Gregory, be patient, your time will come, you cannot play all the games'.
"When you get older, you realise that with extra experience because Liverpool are a massive club. Do I regret leaving? Yes. I should have never left Liverpool."