During a gruelling schedule extended through Checkatrade Trophy participation, Kenny Jackett last term fielded four different centre-half partnerships.
The Blues are presently 12 matches into the 2019-20 campaign – and have already tallied five.
A simple statistic which highlights Jackett’s ongoing issues in establishing the defensive bedrock so crucial to the success of any side.
Matt Clarke’s absence is rightly bemoaned, similarly so is Jack Whatmough’s continued sidelining since February, an injury which cruelly curtailed his finest run of form for the club.
Nonetheless, the contingency plan was implemented in the summer, with Paul Downing and Sean Raggett identified as replacements.
Before the opening friendly at UCD, the duo were pulled aside during the Dublin pre-season tour and informed of their installation as first-choice pairing, likewise Christian Burgess incurred the bombshell he wearily anticipated.
Following 10 competitive games, they were jettisoned, the fit-and-available Raggett removed from the 18-man squad, while Downing sunk to the bench.
And with it, meticulous pre-season planning lay in tatters.
The most recent incumbents, Oli Hawkins and Burgess, started brightly, until separated 59 minutes into their second outing together through injury.
Hawkins’ foot injury sustained against Southampton in the Carabao Cup defeat rules him out for up to six weeks. The unfortunate Jackett must again glance around his changing room for the centre-half solution.
Potentially partnership number six of the season will be unveiled for Bolton’s visit, although realistically Pompey’s boss will revisit a double act previously employed and formerly scrapped.
Compare the scenario to last term when, despite defensive deficiencies during the second half of the season, the Blues still managed to amass 88 points, fourth spot and the Checkatrade Trophy.
Such was the reliability of the centre-half pairing, only two combinations were used during their entire League One, FA Cup, Carabao Cup and play-off programme – shared between Clarke, Burgess and Whatmough.
Even then, Burgess and Whatmough never started a single match together.
Chiefly, the centre-half pairing were Clarke and Whatmough, registering 11 clean sheets in 30 outings in all competitions, before prised apart in February, when the latter sustained knee cartilage damage.
In fairness, Burgess admirably stepped up, producing the finest form of his League One time with the Blues, resurrecting the League Two title-winning relationship with Clarke.
Their 27 matches yielded five clean sheets, although largely coincided with a general defensive malaise for Jackett’s team post-Christmas.
It was the Checkatrade Trophy which saw a greater rotation in the centre-half position, with an additional two different double acts used in five matches along the march to Wembley.
Burgess lined up with Matt Casey for three of those fixtures, the latter a home-grown youngster awarded his Pompey debut in the process – and definitely impressing.
Meanwhile, the ever-versatile Anton Walkes found himself as Burgess’ companion in two matches, including a 3-2 victory over Spurs under-21s at Fratton Park.
To reiterate, four different central-defensive combinations during the complete season, totalling 19 clean sheets in 62 matches.
Pivotal to Pompey’s implosion at the top of League One last term, however, were developing defensive frailties.
On December 8, 2018, following a 2-0 victory over Southend, the Blues soared six-points clear of second-placed Luton with a game in hand.
At that juncture, after the opening 20 league games, Jackett’s men had recorded eight clean sheets and conceded just 15 goals, representing the best defensive record in the division.
Compare that to the final 20 league fixtures, not including the play-offs, when the outcome was three clean sheets and 27 goals let in.
The final League One table reflected a Pompey side possessing the fifth-best defence – and having conceded 12 more goals than second-placed Barnsley.
Clearly the defensive susceptibility currently demonstrated by Jackett’s side is not merely a blip, it has now dragged on for approaching nine-and-a-half months. Worryingly, there is still no sign of it being resolved.
During Pompey’s opening seven league matches of the present season, there have been 10 goals conceded and one clean sheet.
Comparing them to League One rivals is difficult, considering the Blues possess two or three games in hand on the majority following three postponements.
Nonetheless, leaders Ipswich (4) and second-placed Coventry (9) are setting the pace – having both completed two matches more.
In the meantime, Jackett continues to shuffle his centre-half options, hoping to unearth a reliable double act to provide the foundations to fulfilling automatic promotion aspirations.
The season kicked off with Downing and Burgess paired for the opening five matches, producing the sole clean sheet so far, a 2-0 home victory over Tranmere.
Raggett’s maiden start arrived in the 3-3 draw against Coventry, selected alongside Downing in an encounter which saw the Blues surrender a 3-1 advantage over a side which would finish the game with nine men.
The 26-year-old had been recruited from Norwich on a season-long loan, yet considerably short of match fitness, having twice broken a bone in his right foot during the 2018-19 campaign and not featured for six months.
Incidentally, his matching-up with Hawkins against Norwich under-21s represented a fourth 90 minutes at any level in 2019.
That lack of match minutes has prompted coaches Joe Gallen and Jake Wigley to stage regular extra sessions following training, designed to bring the former Lincoln man up to speed.
Similarly, as 19th man at Wycombe last weekend, he completed an individual workout on the Adams Park pitch before kick-off.
Finally, the other alternative partnership employed by Jackett has attracted criticism, with Tom Naylor dropping back from his familiar central midfield role.
The Pompey skipper emerged through the Mansfield ranks as a central defender, earning a move to Derby following promising displays in the position with the then non-leaguers.
Having combined a defensive role with midfield duties at Burton, he switched to Fratton Park in the summer of 2018 to focus solely as a holding midfielder in Jackett’s preferred 4-2-3-1 system.
Following experimentation during pre-season, Naylor was employed there alongside Downing against Blackpool, Burton and QPR.
Then the spotlight fell on the Hawkins/Burgess axis, despite Hawkins being a centre-forward by nature, albeit armed with a CV detailing sporadic defensive outings.
Still, fate has decreed that is short lived, the injured 26-year-old expected back available in November.
Who next enters the revolving doors? And the fact that question is still being asked is a huge concern.