Portsmouth fans left considering the cost after Brighton thumping and Jack Whatmough's exit

His desire to develop understandings was behind restricting changes, as his team punctuated their early-season League One obligations with the stiffest test of their defensive mettle at their Premier League neighbours.

One of those key areas was at the back as Jack Whatmough continued in an effort to build an understanding with Sean Raggett - before leaving the pitch uncomfortably.

It was a concerning sight given the Gosport lad’s injury history but seemingly not a traumatic exit, although we will await updates on that front.

The second half events were disturbing enough once the goals started mounting up for a free-flowing Brighton side.

The manner in which Pompey were pulled apart need not unduly concern, with the gulf in class between the divisions what you would expect.

How much it would’ve taken out of the away side’s legs as they spent long periods of the evening trying to stifle the Seagulls’ mastery of possession remains to be seen, however.

And with the overwhelming priority league points, that was the thought which sprung to mind with it less than 72 hours until the trip to the north west to face Rochdale at Spotland this Sunday.

Jackett’s side gave a good account of themselves in the first half as they made their way along the A27 to take on their affluent neighbours at the Amex Stadium.

The challenge was everything the Pompey boss - and just about everyone else - anticipated.

Graham Potter’s side probed away, moved the ball with purpose and looked for the openings to present themselves.

So it was always going to be about how well the Blues kept their shape and denied their opponents space.

That they did impressively well for most of the 45 minutes against competition who could afford to make 11 changes, and still include their £18m record signing Alireza Jahanbakhsh in their starting XI.

Alexis MacAllister’s header eight minutes before the break negated the dogged defensive work, goal-line clearance from Jack Whatmough and efforts of Craig MacGillvray.

But Pompey couldn’t maintain the rearguard action, and once they were twice quickly breached after the restart the longing started for the full-time whistle.

Before that arrived Viktor Gyokeres had profited from sloppy defending from James Bolton to add to the deficit.

The quiet pre-match ambition was for Pompey to exit the competition with a degree of pluck, before focussing on more important matters.

It didn’t quite work out that as early hopes of a rearguard action stretching late into a chilly summer night dissipated.

Instead we just keep our fingers crossed on Whatmough’s fitness and the Blues limbs recovering well when it’s crucial league points at stake on Sunday.