Jim Mallinder blamed a lack of cohesion for Saints’ defeat at Sale - and said they didn’t get off the coach during a damaging first half.
The Sharks scored three tries before the break, with Mark Cueto, Marc Jones and Tom Brady punishing Northampton to secure a 19-6 half-time lead.
Saints totally dominated the second period, but couldn’t force their way over the line as they saw their 11-match Aviva Premiership winning streak come to an end.
And Mallinder, who threw his six Six Nations stars straight back into the side on their return from international duty, admitted it was a below-par display.
“It was a poor performance,” said the Saints boss. “First half, we never really got off the coach. Sale scored some good tries, took their opportunities.
“Second half, we improved, but we were always up against it because at 13 points behind we knew we had to score tries.
“Sale worked very, very hard during that second half and with (David) Seymour and (Dan) Braid on the field, they were always going to slow our ball down.
“When it gets a little bit slippy and wet like that it is difficult to play and our lack of cohesion showed. We looked like a side who have not played together for the last eight weeks.”
Sale boss Steve Diamond said Saints’ international players looked ‘knackered’ after hailing his own side’s brutality.
But Mallinder disagreed with his counterpart’s assessment that fitness was the deciding factor.
“I don’t think it’s fitness because those lads are fit lads,” he said.
“We just couldn’t string anything together. It was teamwork that let us down, not fitness.”