The Exeter boss will take his side to Sixfields on Saturday, where they will face a Northampton side that has won just once this season in League Two.
However, Tisdale believes that Boothroyd's men will quickly begin to improve, starting with this weekend's match.
"We're only six games into the season, so I don't think we can assume their performance will be bad all year," Tisdale told Exeter's official website.
"Northampton have got some good players, a good manager, they know what they're about and they've had a sticky start.
"You could say that they'll be at their most dangerous currently. We will of course look at their previous games leading up to our match and we will of course look at their form."
Boothroyd led Northampton to last season's playoff final, where they lost to Bradford City.