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.
5. Ben Tollitt (triallist)
Made 12 league appearances for Pompey in 2015/16 before joining Tranmere Rovers on loan. He signed for them permanently in December 2016 and spent three years there before being released last season. Signed with Blackpool in June. Photo: Pete Norton
6. Brian Murphy (signed from QPR)
Murphy had played for QPR for four years before joining Pompoey but only made two league appearances. After a year with the Blues he left with Cardiff City where he was a back-up goalkeeper in the Premier League last season. Photo: Pete Norton
7. Adam McGurk (signed from Burton Albion)
McGurk was highly rated at Burton Albion but scored only twice in his sole season at Fratton Park. Now playing for Coalville Town in the Southern League Premier Division Central. Photo: Harry Trump
8. Ben Davies (triallist)
At Pompey for one season but made quite an impression, finishing runner-up to Michael Doyle in The News Player of the Season award for 2015/16. Left for Grimsby after failing to agree terms and joined Cleethorpes Town in July. Photo: Joe Pepler