He’s not the first to leave Fratton Park to join up with his former manager. We’ve had a look at what happened to all 28 permanent signings Cook made during his time in PO4.
9. Kyle Bennett (signed from Doncaster Rovers)
After playing more than 100 games for Pompey Bennett left for Bristol Rovers in January last year. He scored his first goal for Rovers a week later and spent last year on loan at Swindon Town in League Two. Photo: SCC
10. Kal Naismith (signed from Accrington Stanley)
Another one that got away. Naismith scored 13 goals as Pompey clinched promotion in 2017 but rejected a deal from the club last summer. In May 2018 he signed for Wigan Athletic. Photo: Joe Pepler
11. Gary Roberts (signed from Chesterfield)
Roberts has actually played under Cook for three clubs, including Chesterfield, Pompey and current club Wigan. Interesting fact - he played for England C four times as a non-league player at Accrington Stanley. Photo: Joe Pepler
12. Christian Burgess (signed from Peterborough)
Another Pompey hero from the 2016/17 League Two campaign. In his first season Burgess played 43 games in all competitions and played a major part in last season's run-in after an injury to Jack Whatmough. Photo: Joe Pepler