And three remains the magic number as far as the Blues head coach is concerned, with a right-sided centre-back, a creative midfielder and a striker still on his transfer wish list.
Cowley has managed to bring in 12 new arrivals this summer after initiating a squad overhaul at the end of last term.
All but injured duo Liam Vincent and Jayden Reid, along with Louis Thompson, have featured for he Blues and contributed to their unbeaten start to their league campaign.
Seven of those new faces, in fact, started Saturday’s goalless draw at Doncaster Rovers.
The stalemate at the Keepmoat saw Pompey slip from the top of the table on goal difference, behind new leaders Sheffield Wednesday and second-place Wycombe – with all three clubs boasting 10 points from their first four games of the season.
But regardless of the his new-look side’s impressive start and their adaptability to the head coach’s demands, Cowley remains adamant that further business needs to be conducted.
He told The News: ‘I'll be honest - we're still a long way from where we want to be.
‘We need to try to add to the squad.
‘Categorically, we need three minimum if we want to achieve what we want to.’