Larrieu joined the club as a goalkeeper in 2000, making more than 300 appearances during his playing career.
"I would like to thank Romain and Kevin for the support that they have given me since I have been at the club," he told their official website.
"I could not have asked for more. But it is my job as a manager to make the decisions that I think are going to push the club forward."
Larrieu made his final appearance as a Plymouth player in last season's closing fixture against Cheltenham Town.