Jim Mallinder admits Luther Burrell and George North are not playing to their full potential this season.
And he has called on the talented duo to step things up in the coming weeks as Saints look to breathe new life into their Aviva Premiership top-four bid.
Mallinder was asked about the form of the duo after his side’s shock 25-23 defeat at London Irish on Saturday.
And the Saints director of rugby said: “We are working hard at getting all those players back to playing the way we know they can play.
“You just look at the work rate - you look at George North and we see his figures each week in terms of how much he’s running and the speeds he’s reaching - both George and Luther are working hard.
“I don’t think they’re quite playing the way they want or we want at the moment.
“You just want them to play for 80 minutes consistently well, or very well.
“We’ve seen some good things from both of those players over the last few weeks, but we need to see it more often and that’s what we’re looking for.”
And when asked whether Burrell, who was replaced during the second half, is trying too hard, Mallinder said: “Potentially.
“He’s got to play really well to get back into that England setup, he’s very conscious of that and he is doing his best.”