"Winning games breeds confidence and on the back of a good win at Huddersfield we go into the Millwall game full of confidence," he told the official website.
"We put in an unbelievable performance on Saturday and full credit to the players they bounced back really well from the disappointment of the defeat at Doncaster.
"Overall I think we perhaps dealt with the conditions a bit better on Saturday and the manner of the victory was very pleasing."
Northampton have ended the year in 16th place in League 1. Nine points behind the play off places and 7 points ahead of the relegation zone.