Northampton Saints flanker Ben Nutley admits the Premiership leaders are struggling to find their best form.
Saturday's 20-7 defeat by Sale followed hard-fought victories over Newcastle, Harlequins and Leicester.
"We weren't at our best. But we haven't been at our best for a while," 22-year-old Nutley told BBC Radio Northampton.
"We need to get back in this week, have a look at ourselves and sort out the problems we know we can sort. We've got the squad to sort it."
Saints have not been at their fluent best since the 67-0 destruction of Treviso on 13 December,
The victory over Leicester was secured despite playing most of the game without captain Dylan Hartley, who was sent off, but Jim Mallinder's men again had to call on their battling attributes against Quins and Falcons.
And the loss at Sale, which allowed Bath to close the gap on the leaders to a point, means Saints have conceded 20 tries in their last seven Premiership matches, compared to seven in the previous six.
"We are top of the league, but we can't just write this defeat off," said Nutley.
"We've been giving lip service to our defence and how we've conceded more tries in the last few weeks than we have all season.
"We have to really look at it, we can't keep saying it's going to work. We have to watch the video and if we have to pick out players, that's the way it is."