The Cobblers picked up their first win under Johnson last weekend to secure their place in the Football League and the former Bristol City man is set to make sweeping changes to the squad in the coming months.
He said: "I have spoken to a few of the players that we won't be offering contracts to but I think it's best for that news to wait until after the weekend.
"I have thanked all of them for their efforts but the position that we were in we can't be in again and we have got to bring in quite a few fresh faces.
"I've had a good chance to look at everybody in the squad and I've seen how they can cope both physically and mentally. That is really important because if you are going to put a promotion winning team together you need players who are going to be mentally tough.
"We want to try and do our business as early as possible and we have been looking at players over the last four or five weeks. I want to entertain, it can take time to bring in those types of players and they need to have that work rate as well."
Source: PA
Source: PA