No surprise to see a new-look back four wobble but zeroes and ones will return

Zeroes and ones. That’s what Kenny Jackett consistently preaches when it comes to Pompey’s goals-against record, writes Will Rooney.

The boss firmly believes if the Blues concede no more than once per game then they’ll stand a firm chance of being promoted.

But in the past two fixtures Pompey have been unable to meet Jackett's demand.

The Blues conceded twice in their defeat to Sunderland on Saturday — and three times in Tuesday’s painful draw with Coventry.

That's in stark contrast to last term when it took Pompey until their ninth game to concede twice in a match— a 2-2drawwith Wycombe on September 22.

The Blues were certainly found wainting in their defensive performances at the Stadium of Light and against the Sky Blues.

As Gareth Evans pinpointed, the collapse against nine-man Coventry was nowhere near good enough.

But it's not a major surprise at this formative stage of the season.

Matt Clarke and Nathan Thompson have left — two defensive mainstays in the past two campaigns.

Their departures were always going to impact the Blues. And not just because of their ability.

They had built up a sound

rapport with the likes of Lee Brown, Christian Burgess and keeper Craig MacGillivray.

Five games into the new season, Jackett has used eight players in his back four and is still searching for his favoured centre-back partnership.

In fairness, Paul Downing has started the campaign fairly well since his summer arrival.

Sean Raggett, who came in for Christian Burgess against the Sky Blues, looked rusty. Understandably so given his injury hampered start to the season. Burgess, meanwhile, may well have felt aggrieved to be dropped. He’s barely put a foot wrong. Rightback Anton Walkes was axed completely following a disappointing performance at Sunderland. His replacement, Ross McCrorie, is primarily a midfielder. And after an impressive cameo at the Stadium of Light, the Rangers loanee had a mixed night against Coventry.

Jackett will be hoping James Bolton can be the remedy when he regains full match fitness.

The early defensive performances have unsurprisingly caused angst among sections of fans.

But once Jackett does find his regular back four, you’d expect those coveted zeroes and ones to arrive more frequently. Eight players have played in the back four in the first five games