Former Pompey player, Mick Kennedy, has died at the age of 57.
The midfielder was part of the side that secured promotion to the top-flight in 1987.
He arrived at Fratton Park aged 23 and had already racked up more than 200 league appearances for Halifax, Huddersfield and Middlesborough.
When Alan Ball was appointed manager in the summer of 1984 he paid £100,000 to make Kennedy one of his first signings.
The club said: "He added much-needed aggression to the centre of the pitch and following to near-misses, finally helped Pompey return to Division One.
"The big question for fans was whether they could stay there, but the job was much harder when, against both his and Ball's wishes, Mick was sold to Bradford for £250,000 midway through the campaign."
Kennedy's final game for the Blues was a memorable one with Southampton beaten 2-0 at The Dell.
Pompey only one two more league games that season and many supporters still point to the sale of Mick - who won two Republic of Ireland caps during his time at the club - as the reason for their relegation, according to the club.
Mick Kennedy appeared 1⃣4⃣4⃣ times for #Pompey during a four-year spell, helping the Blues win promotion to the First Division in 1987.— Portsmouth FC (@officialpompey) February 10, 2019
He was inducted into the Pompey Hall of Fame last year ⬇️ pic.twitter.com/cl3ZVeOAmI
Kennedy was honoured for his contribution to Pompey last year when he was inducted into the club's Hall of Fame.
The club say the thoughts of everyone at Portsmouth FC are with Mick's family and friends at this sad time.