A 3-1 defeat at Sixfields means the Cobblers are still not mathematically safe in League Two and also provided a setback to Boothroyd's belief that his side are heading in the right direction as next season approaches.
"Bradford deserved their win, they outfought us all over the pitch and I never like to say that about my teams," he said afterwards.
"We had several efforts cleared off the line and hit the bar twice, that makes it sound as though we played well but we didn't."