The Blues head coach explained the players he currently has in his sights are beyond the club’s financial reach at present.
But Cowley is hoping the final additions he is eyeing can fall within the confines of his playing budget, before the close of the window.
The 42-year-old is having to play a waiting game when looking at recruits from the Championship, and what he can realistically expect to offer in terms of wages.
That approach has already seen players lost to rivals, with a real possibility the same could happen again before August 31.
But the Londoner has continually made it clear he will not be willing to compromise on quality - and he is not contemplating conceding ground on that approach now.
Cowley said: ‘I think there are one or two who are possibly available, just not within our financial capabilities at the moment.
‘We’re just having to wait and hope the prices come down.
‘It would need to be half, more than half, possibly two thirds.
‘I know we’ve had a good start, but we need a minimum of three to achieve what we want to achieve.
‘We want three key players for three key positions. We know the type of players and the profiles we want.
‘It’s really just to help the boys we’ve already got in the group.
‘There may naturally also be interest in or two of ours, you’re never quite sure. We’ll have to wait and see.’
With less than two weeks to go, judging how the rest of the transfer window unfolds is going to be key to how things play out for Pompey.
But Cowley admitted anticipating how the market moves has not been a straightforward task so far.
He added: ‘It’s been really slow.
‘I can’t believe we’ve got this far without anything really happening in the Premier League, besides a couple of big ones, of course.
‘Other than there’s been very little and it’s been the same in the Championship.
‘Blackburn have sold Armstrong and we anticipated them being quite aggressive, but they haven’t been as yet.
‘I think it will move, it always does. Time will tell if it will be at the speed we want.
‘We’re coming off the back of an international tournament,a deep window and clubs are holding on to what they’ve got because of the pandemic.
‘That’s the new and uncertain element to it all.
‘I’d always be comfortable with 22 and even I’m not comfortable with that number, so that’s a factor.’
A message from the Editor, Mark Waldron
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