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…
1. 13) Lloyd Isgrove
The winger arrived on loan from Barnsley in January 2019. However, Isgrove imfamously didn't make a single appearance for Pompey and was included on the bench only twice. He returned to Oakwell before the play-off semi-final against Sunderland. He's now at Bolton after helping Swindon to the League Two title last season. Photo: Joe Pepler
2. 12) Stephen Henderson
The keeper made a shock return on loan from Nottingham Forest on deadline day in January 2018. Henderson started Pompey's next game against Doncaster but suffered an unfortunate season-ending thigh injury. Henderson's now at Crystal Palace where he serves as a back-up stopper. In truth, when he arrived the Blues didn't need a replacement for Luke McGee and instead needed a centre-midfielder. Photo: Joe Pepler
3. 11) Sylvain Deslandes
The France youth international arrived from Wolves early in the January 2018 window with team-mate Connor Ronan. However, the left-back played only twice for Pompey - and was substituted on both occasions. He failed to solve Pompey's problem on the left-hand side of defence that season. Now at Romanian side Argeș Pitești. Photo: Joe Pepler
4. 10) James Vaughan
The striker moved to Pompey from Wigan on deadline day in January 2019. The striker arrived only as cover, however, and failed to score in 11 appearances and split his time training with the Blues and the Latics. The ex-Everton man's been in prolific form for Tranmere this season, bagging 13 times. Photo: Joe Pepler