Jim Mallinder admits the top four now looks a ‘fair way off’ for Saints.
And the director of rugby has told his team they must beat Worcester at Franklin’s Gardens on Saturday as they bid to get something out of their season.
Saints dropped down to eighth in the Aviva Premiership standings after slumping to a 46-31 defeat at Newcastle Falcons on Sunday.
Mallinder’s men shipped a total of seven tries, five of which came after half-time, as they surrendered a 24-10 lead at Kingston Park.
It means Saints have now suffered back-to-back league defeats, having previously lost at Bath, conceding a total of 11 tries during the two games.
And Mallinder said: “We need to win this week.
“We’ve got small targets and the top six is what we need to get back into.
“We’ve got Worcester this week and we need to work on our defensive game.
“We talked at the beginning of the season about how our attack wasn’t functioning, we weren’t scoring tries, but we were defending and doing well.
“We’ve really had a flip of the coin over the last few weeks.
“We’re now scoring lots of tries, but we’re conceding lots of tries.
“We need to improve our defence because that certainly let us down on Sunday.”
Saints are now 12 points off fourth place, and two behind sixth-placed Harlequins with seven games of the regular season to go.
And on his team’s ambitions for the remainder of the season, Mallinder said: “It (finishing in the top six) is the next target.
“Top four now looks a fair way away, but what we need to do is come back and make sure we get a win against Worcester.
“We need to start climbing the table again.
“We’ve still got a number of games.
“It’s never easy in this international period to play three games out of your four away from. Ideally, you’d have at least two at home or three at home, but we’ve got three out of four, which is tough, so we need to make sure we get back to winning ways this week.”