A tactical switch from his preferred 4-2-3-1 system helped secure the Blues’ first win of the season against stubborn Colchester on Saturday.
Cook had set up his side anticipating an open game, only for the U’s to replicate many predecessors in arriving on the south coast content with collecting a point.
On the hour mark, though, Pompey’s frustrated manager switched to a 4-4-2 formation, with Gary Roberts’ late double – the first arriving from the penalty spot – securing a welcome 2-0 success.
And Cook is now in agreement with Blues fans that he must abandon his footballing philosophy to help make Fratton Park into a fortress.
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He said: ‘It is hard to score against 11 men behind the ball – that’s what we are getting now at home.
‘The reality of it is I have always had an ethos and a philosophy on the game but I have to look to change it.
‘For me to be a successful Pompey manager, I must look at changing.
‘That’s because it (4-2-3-1) doesn’t work to the extent where we have scored goals early in games and won.
‘I can’t offer that argument. The fans are right.
‘They want us to win. And we have to play a bit more basic football and put teams under more pressure with balls into the box.
‘And I am going to do it. I genuinely am going to try my best to do it for them.’
The introduction of fans’ favourite Conor Chaplin and fellow striker Noel Hunt saw the Blues end Saturday’s game with two up top.
And for Cook, it was a positive change that helped to lift the growing sense of frustration at Fratton Park.
The Pompey boss said: ‘We changed the formation and won 2-0.
‘It worked better but it is clear for everyone that teams dont engage in a football match with us.
‘And then our crowd’s frustration can lead to player frustration – and we can’t afford to get frustrated.
‘We know what we are getting involved in now.
‘And our fans are right – we need more penetration.
‘We need more oomph.’
While Cook may be happy to change systems, he will not be compromising his winning mentality.
That’s despite the mindset of many of the Blues’ League Two rivals.
He added: ‘Our fans know we don’t turn up at any ground in any game to try to defend.
‘We turn up to have a football match.
‘But the reality of it is we are Portsmouth Football Club and it is not happening at home. We must get over it.
‘My job and my staff’s job is to look at it now.
‘I always believed we could break teams down and we would be all right.
‘But on Saturday there was a point in the second half where it was quite clear it wasn’t working.’