Jack Whatmough has taken to Twitter to bid farewell to Pompey after agreeing a switch to Wigan.
The defender will join the fellow League One club when his Blues contract expires at the end of the month.
He said: "After 13 years, my time at Portsmouth has come to an end. I'd like to thank you all for the support through good and bad times. It's something I'll never forget.
"I wish Danny, Nicky and the club all the best moving forward and hope they bring success, which the club deserves.
"It was an honour to represent the football club and wearing the badge was always something I took pride in.
"To all the fans, board, players past and present, thank you. It's been a pleasure. I've met lifelong friends and some people I'll never forget."