Matt Clarke expects Northampton to offer a sterner test than Wimbledon as Pompey head for the road again.
The Blues travel to Sixfields tonight (7.45pm kick-off) for their second League One away-day fixture in four days.
Saturday’s 2-0 win at Wimbledon saw Pompey pick up their first win on their travels this season.
The victory also produced only the second clean sheet for Kenny Jackett’s side this term.
Clarke was a key figure in that shut-out as his central-defensive partnership with Christian Burgess continues to boost the Blues.
However, the former Ipswich man believes Pompey were rarely troubled at Kingsmeadow.
And he expects tonight’s hosts to be more dangerous on the front foot under new manager Jimmy Floyd Hasselbaink.
Clarke said: ‘I felt we were solid as a unit (against Wimbledon) and hopefully we can pick up more clean sheets.
‘But I think we will have bigger tests than that.
‘If I am honest, I don’t think Wimbledon threw much at us and didn’t have that much quality.
‘It was just pleasing to get a clean sheet and a win.
‘Now we’re looking at Northampton. Wimbledon wasn’t too far away and we’ve been lucky that it hasn’t been two really northern slog trips.
‘They have a new manager and won at the weekend – but we will go at it.’