Lee Bradbury has warned Pompey: Maidenhead will be hard to beat.
The Blues travel to the National League strugglers in the first round of the FA Cup on Saturday.
It’s a game Kenny Jackett’s League One table-toppers are fully expected to win.
The Pompey boss ran the rule over Alan Devonshire’s side when they played the Hawks at Westleigh Park last week.
Bradbury’s troops routed Maidenhead, recording a 7-0 victory.
The visitors, however, had goalkeeper Carl Pentney sent-off in the 36th minute, forcing Alan Massey to act as a makeshift stopper.
The Hawks boss has insisted his side’s romp wasn’t a full reflection of Devonshire’s outfit.
And Bradbury feels Maidenhead will be more competitive when they face the Blues in the FA Cup.
He said: ‘I would expect Maidenhead to be a lot more competitive in the Portsmouth game.
‘Alan Devonshire is a cute manager and he will set them up in a way to be hard to beat.
‘What formation that will be remains to be seen but they will try and stay in the game as long as they can.
‘Their confidence will have taken a hit though after two successive heavy defeats- 6-0 and 7-0.
‘I don't think they can be taken as a true reflection heading into the Portsmouth game.
‘Against us they had their goalkeeper sent off and that didn't help.’