Cobblers boss Keith Curle felt that the red card changed the game in Saturday’s 2-0 home defeat to Doncaster Rovers.
“The game was quite evenly matched until the sending off,” he said.
“The first goal was a gift and apart from that I didn’t think Doncaster caused us too many problems.
“I know Shaun (McWilliams) will tackle anything and anybody and we don’t want to take that enthusiasm away from him. There was no malice in it, he saw an opportunity to go and win the ball and he went for it.
“Sometimes games don’t go how you want to but I still thought it was a very committed performance.
“It was great to have some fans back and it was just disappointing that we couldn’t get the result for them but that will come and the fans will play a massive part for us this season.
“This is going to be a season where we will need a unity between the players and the supporters and I know with this football club that we can get that.”