Pompey are releasing 10 players whose contracts expire this summer.
Michael Brown, Darryl Flahavan, Billy Goddard, Pete Gregory, Richard Hughes, Tom Kilbey, Ellis Martin, Marlon Pack, Perry Ryan and Danny Webber are all leaving Fratton Park.
Former Manchester United, Watford and Sheffield United striker Webber joined the Blues in September 2009, scoring three goals in 32 appearances.
Hughes played 165 games after arriving from Bournemouth in the summer of 2002, but had to wait until last December to score his first league goal in a 3-3 draw at Leeds.
Fellow midfieder Brown scored five goals in 57 appearances during his two years on the south coast, including a memorable solo effort in the 6-1 thumping of Leicester in September.
Flahavan – the brother of late Blues keeper Aaron – joined the club in August on a month-to-month deal as back-up to goalkeeper Jamie Ashdown, but did not make a first-team appearance.
Pack – who has enjoyed a successful loan spell at League Two Cheltenham – Gregory and Kilbey all made a handful of first-team appearances last season, with the latter scoring in the Blues’ FA Cup defeat at Brighton.
Ryan, Martin and Goddard all leave the Blues without making a senior appearance, although Goddard will continue to train with the club to aid his recovery from a serious knee injury suffered in a friendly at Havant & Waterlooville in November.