The Blues have so far recruited 11 new faces this summer with Marlon Pack, Colby Bishop and Dane Scarlett the pick of the bunch.
With his side still in the market on the final day of the window, there’s still plenty of anticipation ahead of the 11pm close.
After the formation of the transfer window in the 2002-03 campaign, deadline day has been well-known to Pompey fans whether it was in the Premier League days with Harry Redknapp or with Paul Cook in League Two.
We’ve taken a look at 10 standout signings who were memorable for all types of reasons - even if it didn’t work out on the pitch!
Here’s what we found.
9. Michael Smith
The striker arrived on loan from Northampton in January 2016 as Paul Cook looked to strengthen his attacking ranks. After a promising six months at Fratton Park, which saw him score four goals in 16, the striker made his move permanent. Yet, he failed to rediscover the same form abd would go on to join Bury 12 months later. Photo: Harry Murphy
10. Mahlon Romeo
Romeo joined the Blues on deadline day 12 months ago on a season-long loan from Millwall. His arrival surprised many with Cowley repeatedly ruling out a move for the full-back before he was announced late in the evening on deadline day. He would go on to feature 41 times last term before returning to The Den. Photo: Graham Hunt