Mallinder’s men crashed out of the domestic cup competition with a disappointing 28-19 defeat at Exeter last weekend.
It followed on from Saints’ failure to progress in Europe two weeks earlier, as defeat at Glasgow cost them a spot in the Amlin Challenge Cup quarter-finals.
Now, only one focus remains: Premiership glory, starting with a game against top-four rivals Gloucester at Franklin’s Gardens on Saturday.
And Mallinder said: “We’re out of the LV= Cup, which would have been nice to have been in, but we’re in an unusual position now of just being in one competition.
“During the past few years it’s now something we’ve been used to.
“We’ve been fighting on most fronts and now we’ve got a clear focus and that has got to be our only focus.”
Like Saints, Gloucester also suffered LV= Cup defeat last weekend, losing 32-5 at home to Bath, who beat Northampton to top spot in Pool 4.
Mallinder knows the Cherry and Whites will be hurting just as much as his side, but is desperate to come out on top on Saturday, with a crucial run of games getting underway.
“I think Gloucester will be equally frustrated in terms of losing at home,” he said. “It’s a massive game.
“Things change because you then put your top sides out. We’ve made a few changes, which has freshened things up, and we’ll be full on.
“It’s really important because the next few league games will have a big influence on where we finish.”