During the past three winter windows, the Blues have been unable to add the necessary players required to deliver League One promotion.
Pompey were sixth on New Year's Day during Jackett’s first season in charge in 2017-18 but would go on to finish eighth.
They sat top at the turn of the year the following campaign but dropped to fourth and suffered play-off semi-final defeat to Sunderland.
And while the Blues moved up from ninth to fifth last term, they again lost in the play-offs to Oxford on penalties.
It total, Kenny Jackett had made 13 signings in the past three January windows.
In truth, the majority of the players recruited haven’t worked out at Fratton Park.
There have been a few who’ve impressed, however, while one signing is very much for the future.
We’ve had a go at ranking those who’ve arrived midway through the season – from worst to best. Scroll down to see our list…
5. 9) Connor Ronan
Joined on loan early in the January 2018 window from Wolves. Ronan was held in high regard by his Blues team-mates and showed glimpses of his talent in his 17 outings. However, he didn't quite live up to expectations and struggled to meet the physical demands of League One. Now on loan at Swiss side Grasshopper. Photo: Joe Pepler
6. 8) Viv Solomon-Otabor
There was plenty of excitement when the winger arrived in the 11th hour from Birmingham in January 2019. Solomon-Otabor had wreaked havoc against Pompey while on loan at Blackpool the previous season. However, he never quite got into a rhythm at Fratton Park, scoring once in 10 games. Will be remembered for that offside goal against Peterborough. Solomon-Otabor's now at Wigan. Photo: Robin Jones/Digital South
7. Bryn Morris
The midfielder joined the Blues from Shrewsbury in January 2019, having previously been lined-up to go to Luton. However, things haven't quite worked out for Morris at Fratton Park. He's been limited to just 26 games, scoring one goal, and had a torrid time with injuries. Morris is currently down the pecking order and an arrival of a midfielder this January could render him surplus to requirements. Photo: Joe Pepler
8. 6) Omar Bogle
The striker arrived from Cardiff on loan in January 2019. Bogle started off like a rocket, netting four goals in his opening eight games. Howver, he failed to bag in his subsequent six matches and suffered with various injuries. Now represents League One rivals Charlton. Photo: Joe Pepler