Colby Bishop was nowhere to seen, instead replaced by an imposter channeling the ghost of Scott McGarvey, Collins Mbesuma, Hamilton Thorp and all the other maligned strikers to have worn the star and crescent on their chest down the years.
The Magic Man had gone from poacher to profligate, as John Mousinho’s side passed up a swathe of first-half chances. In fact, the shot count had reached a bloated 13 by the break, with Bishop the chief culprit when it came to wasted opportunities.
Then Pompey’s performance faltered and, quite possibly for the first time this season, they could count themselves second best to foes finding life in League One a far from straightforward affair, after their play-off success last term.
Craftsmen like Abu Kamara and Paddy Lane faded. Impactful reinforcements like Christian Saydee and Kusini Yengi toiled.
The cohesion and fluidity which have become bywords for Pompey’s performances this term was washed away in the autumn rain. Instead, indecision and a lack of clarity had become the Blues’ bedfellows.
Roberts would have seen faults to exploit and not a great deal to be concerned about, as the League Two title winner returned to PO4 on a reconnaissance mission ahead of next month’s Chesterfield FA Cup trip.
Yet, this Pompey have established certain characteristics amid the 24 unbeaten league games and form which now has supporters firmly believing.
And enough of those traits were still present to make the difference and plunge a dagger into the hearts of the 676 excellent Carlisle fans, who had made the 700-mile round trip and backed Paul Simpson’s side so fervently.
Conor Shaughnessy’s late, late winning header - his second this month - is the fifth time Pompey have struck in stoppage time this season. Eight points have now been harvested as a result.
The impressive defender’s repeat of his 98th-minute effort against Wycombe is now the EIGHTH corner Mousinho’s side have bagged from in all competitions, in addition to the free-kick Kusini Yengi headed home against Gillingham in the EFL Trophy.
Then there’s the teasing and tantalising impact of Jack Sparkes.
The left-back’s delivery was once again on the money when it mattered - with the Exeter signing now providing a whopping six assists in all competitions.
The man generating such optimism is proving a hard taskmaster, however, with Mousinho's remarkably honest and balanced post-match assessments now a hallmark of his tenure.
‘I thought Carlisle were excellent,’ acknowledged the Pompey boss in the immediate aftermath of victory.
‘I felt they could and should have felt that they were very unlucky not to have come away with at least a point. They caused us problems and controlled the game more than we did.
‘It’s honestly the first time this season I’ve come away from the game thinking we nicked it, and didn’t quite deserved what we’ve got.
‘I think the 12 other games have been fair results, and maybe we should have turned a draw or two into wins. But this time I feel we’ve been slightly lucky and Carlisle can feel slightly aggrieved.’
Such candour has been beyond the reach of many of Mousinho’s predecessors when the blood is still up in the wake of battle. Perhaps the recurring success helps, but there’s enough evidence to suggest an admirable consistency from the boss in his post-match media addressees.
Likewise, the indomitable belief which now courses though his players is palpable, along with an innate conviction there’s rewards to be harvested to the very last second.
It’s creating an accelerating impetus which has now seen a three-point gap open at the top of League One, and, crucially an eight-point chasm to third place.
The next week presents league challenges on the road, which offer the opportunity for further reward to extend a seven-game winning run and equal the club’s nine-game record. It rarely works out quite that simple in practice, of course.
But the feeling of this season’s possibilities is now undeniable, from the dressing room to every corner of the grand, old gal bathing in optimism.
A quiet storm of royal blue belief is brewing at PO4, one based on a common conviction over this team’s capabilities - right until the game’s last breath.