Pompey have picked up some gems after trial periods down the years, but the Blues have also let some players through their grasp who have gone to have monumental careers in the game.
Here’s a list of some of the most famous - and infamous – triallists from the club’s history, along with some names which may catch you by surprise….
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13. Tyrone Mings
Got turned down at Pompey as a youngster before eventually joining Cheltenham Photo: Nick Potts
14. Michael Mifsud
Malta international turned up at Pompey in 2010 and 2013 but never earned a deal Photo: STR
15. Juan Vargas
Came close to joining Pompey in 2006 but Blues haggled over £1.6m price, he joined Catania and later moved to Fiorentina for 12m Euros! Photo: David Ramos
16. Georgi Kinkladze
Manchester City legend tried to earn a deal in 2003 without success. Photo: The News