Nigel Miller – the scourge of Paul Cook and the architect of a two-match ban from their previous encounter.
With ill-feeling continuing to simmer, there was an inevitability the County Durham referee would once again incur the wrath of the Pompey bench.
Yet Miller’s influence was more contributory than decisive in Saturday’s dismal defeat.
It would be too convenient to parade the match official as the fall guy, for the Blues’ problems extend further than just one man.
Granted, the referee who oversaw August’s defeat at Morecambe played an unsatisfactory part in Adam Campbell’s matchwinner.
With Tom Davies floored and Christian Burgess nudged, the Blues were deprived of their central defensive pairing when Adam Campbell settled the occasion in Notts County’s favour.
The staff howled, the players protested, David Forde earning a yellow card for his remonstration – nonetheless the strike stood.
Undoubtedly the seething Blues had a strong claim for momentary injustice, yet Miller should not bear sole responsibility for a 2-1 loss.
Wastefulness in front of goal, a lacklustre second half and brittle defending warrant equal billing in the inquest into successive league losses at Fratton Park.
Pompey had returned to home turf following an encouraging four points on their travels, including a draw at leaders Plymouth.
Reinvigorated, belief restored and thoroughly deserving of praise during a fortnight away, Saturday represented the opportunity to build on the creation of a decent platform.
Sadly that sterling work came crashing down in front of the disbelieving eyes of a Fratton faithful who made their feelings known at the final whistle.
They had witnessed a smash and grab act from visitors who barely threatened David Forde in the Blues’ goal and, for long periods, were penned in deep.
Based on their domination, the hosts would have been disappointed with a draw. As it was, supporters were rightly left livid to finish empty handed.
Locating the chief culprit behind a fifth defeat in the opening 14 League Two fixtures remains a tricky task, such were the number of glaring weaknesses.
Indeed, while concerns over Pompey’s inconsistencies have previously been raised, against the Magpies the issue was summed up by contrasting halves.
For the opening 45 minutes they were threatening, energetic, dangerous and dared to deliver a promise of more goal-scoring might after the break.
As it was, Cook’s men bafflingly retreated into a shell during the second half, bereft of ideas, lacking in substance and devoid of urgency.
They pressed hard during the late stages, throwing Christian Burgess up front to take advantage of the visitors’ reduction to 10-men for the last 13 minutes, yet the final ball was massively disappointing.
The Fratton faithful would surely have been enthused at half-time, regardless of witnessing several missed opportunities in front of goal, particularly from Conor Chaplin.
Hence their anger at what was served up in a second period which would yield another defeat, albeit accompanied by controversy.
Elsewhere in Pompey’s make-up remains a porous defence, reflected by one clean sheet in eight league matches.
Individual errors have contributed to a rash of goals conceded in recent weeks and against Notts County the vulnerability was alarming once more.
On 21 minutes, Richard Duffy, a Pompey player from a decade ago, flighted a free-kick over the top which was picked up by Campbell.
The midfielder’s first touch sent the ball behind him and the retreating rearguard, yet he responded by retrieving it and clipping an unchallenged first-time right-foot shot into the far corner.
During the process, the Blues had remained leaden-footed, failing to react, while Campbell’s energy saw him rewarded with the opening goal.
Another entry into a growing catalogue of defensive failings, although intriguingly Adam Buxton, Drew Talbot and Matt Clarke last week returned from injury.
On the flip side, Enda Stevens’ second-half departure through a hamstring problem saw Kal Naismith asked to slot in at left-back from the 59th minute.
It mirrored midfielder Gareth Evans’ continued presence in the opposite full-back berth.
Regardless of the ever-changing defensive personnel, the issue is continuing the ground the Blues and their hopes of finally escaping League Two.
On Saturday, Cook opted to field an unchanged side, despite Clarke’s return to fitness following a groin problem.
Instead the 20-year-old replaced Jack Whatmough on the bench to serve as the centre-half back-up, the only alteration to the squad at Home Park last weekend.
Meanwhile, Chaplin was seeking to mark the signing of a new deal 24-hours earlier to keep him at Fratton Park until 2019.
By the time he registered his fourth goal of the season to level the match in the 27th minute, he could have bagged a hat-trick.
During an encouraging start for the Blues, on six minutes Stevens crossed from the left and Chaplin, three yards from goal and in a central position, somehow steered a first-time right-foot shot wide.
On 13 minutes, a ball over the top sent the teenage striker racing clear, only to fire an effort straight at keeper Adam Collin, who stood tall.
Then came the equaliser, Kyle Bennett charging into the left-hand side of the penalty area before putting the ball inside to Gary Roberts.
The midfielder managed to pull the ball back by the byline and Chaplin was there to slide in a finish from six yards out.
The hosts continued to threaten for the remainder of the half, but were a shadow of themselves after the break.
Bennett should have headed home Chaplin’s cross from the right, substitute Curtis Main headed Carl Baker’s cross straight at the keeper, while in stoppage time Collin brilliantly denied Baker himself.
Yet that was the sum of Pompey’s attacking credentials during a second 45 minutes in which Aaron Collins was dismissed for a lunge on Forde.
As for the Magpies – they had Miller and that Pompey defence to hand them a winner.