And the former Aston Villa striker has questioned the effectiveness of a back-five in attacking positions.
The current Fratton chief has switched between a 4-2-3-1 formation and 3-4-3 this term, with the former utilised in the club’s promising early season form.
But due to injury and selection nightmares, Cowley somewhat prematurely changed to a back three – which has been in use for the past 11 matches.
And Whittingham believes it’s time for a change in order to reignite Pompey’s frontline.
He told BBC Radio Solent: ‘‘(I’m) disappointed with the start they had. First 30 minutes they dominated the game but didn’t create enough chances to win it, though. They didn’t create enough to score one goal, let alone two they needed.
‘Then a mistake at the back eventually cost them again. It’s a conundrum I think for Danny Cowley. With this back five, they’ve been hard to break down, and Sunderland didn’t create much either and Pompey gifted them the goal.
‘When you’ve been fairly secure at the back, how do you know you'll be able to create things going forward and get some goalscoring opportunities? Because they haven’t been able to with a back five.’
During their Stadium of Light loss, Pompey were the architects of their own downfall by failing to create meaningful chances and gifting the hosts their decisive goal.
In what was an overall strong defensive display, Hayden Carter was caught in possession on the edge of his box, before Elliot Embleton’s strike on the cusp of half-time.
But Whittingham believes toothless attacking performances need rectifying, before a defensive reshuffle.
‘Pompey are hard to break down and they’ve given it away themselves today. Sunderland didn’t break them down to create chances and it was Pompey's mistakes. But going the other way Pompey couldn’t break them down.
‘It’s a combination of trying to find the right fit for the attacking players that Danny Cowley has. There’s nobody who has really bang in-form.’
A message from the Editor, Mark Waldron
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