Jim Mallinder was disappointed with Saints' defending after they shipped four tries in a 38-22 defeat to Wasps at Franklin's Gardens.
It was the fourth game in succession that an opposition team has come away with a try bonus point against Mallinder's men.
And it was also the fourth game in succession they have lost in all competitions.
Tries from Ahsee Tuala and Harry Mallinder were not enough to save Saints as they suffered a third defeat in seven Aviva Premiership matches this season.
Wasps were able to celebrate their third win of the league campaign and their fifth in succession against Saints.
And Mallinder said: "Wasps did play well, to be honest.
"They slowed a lot of our ball down, competed for the ball very effectively so we've got to look at our clear-outs there.
"I was also disappointed in some of our defence. We gave them a couple of tries.
"It was a bit of a whirlwind game.
"There were quite a lot of positives in the first half in terms of our possession and carrying over the gain line.
"We did talk about how important it is to manage the game against Wasps because you don't want a loose type of game.
"When you kick you've got to be accurate, contest the ball or get it off the field, but they showed what a good side they are from turnover."