Alan Gaffney says Saints' 'repeat offenders' must front up after ill discipline cost them dear at St James' Park on Saturday evening.
The black, green and gold shipped 14 penalties, 10 of which were in their own half, as they suffered a 25-22 Aviva Premiership defeat to Newcastle Falcons.
Toby Flood kicked six penalties for the Falcons, including the one that eventually won the match.
Saints remained in contention until the final whistle thanks to tries from David Ribbans, Rob Horne and Nafi Tuitavake.
But they could not find a way to score a bonus-point try and secure the win, leaving technical coaching consultant Gaffney frustrated.
"We scored three tries by the 60th minute and that gave us time to score that bonus-point try, but we just didn't have any field position in their half," Gaffney said.
"We've got to get better, we can't be as ill disciplined as we are.
"There are repeat offenders and we've got to front up to that on Monday and address the issues.
"People have to go away and do their own work and report, then we'll look at it in a group situation.
"If someone's got to be embarrassed, someone's got to be embarrassed. We just can't continue the way we're going at the present time, with people repeating the offences.
"We'll take remedial action where possible, whatever it may be."
Saints only conceded one try on the day, with Vereniki Goneva sneaking through a gap during the first half.
But it was the boot of Flood that proved their undoing.
And Gaffney added: "(Defence coach) Phil Dowson has worked very hard on the defence and we defended pretty well.
"We conceded one try to Goneva through the middle of the ruck, which was an error, but across the board we were pretty good in defence.
"We conceded three penalties from restarts and 14 penalties for the game.
"Penalties in the tackle area cost us, like at Exeter, and we're not being dominant in the tackle, we're lying in the tackle area, not getting away and we're getting penalised.
"We've got to get better in that area and we're working pretty hard at it.
"We've got to do something about it."