Tom Wood says it would be "criminal" if Northampton surrender their strong position in the Aviva Premiership title race.
Northampton have suffered three successive Aviva Premiership defeats in recent weeks - all to play-off rivals, Leicester, Sale and Saracens - after a sequence of 11 consecutive victories dating back to October.
The second-placed Saints have three matches left to guarantee home advantage in the play-off.
But with Leicester on their trail - just three points behind them - Saints are under pressure ahead of Sunday's clash with London Irish.
"We have had a brilliant eight months and we have been top of the pile, or thereabouts, for a long time. We have had a huge unbeaten run," Wood said.
"It would be criminal for us to throw it away now and tail off and not get something for all our efforts.
"People haven't seen the best of us this year and it would be a real shame if you had already seen what we have got to offer.
"We have been nearly men for a little while and that is a tag we want to shake off.
"We are a very capable side on our day and we have to make sure we get it right on the big occasions.
"Beating Saracens in the semi-finals last year shows that if we get it right we are a force to be reckoned with.
"But we can't be okay with losing, particularly against big rivals like Leicester and Saracens, as we have done recently."
East midlands rivals Leicester are challenging hard for second place after stitching together a trademark end-of-season run of seven successive Premiership wins.
"Leicester have got a knack of getting it right at the end of season and they are building some momentum now," Wood said.
"We have got things in our hands still - we have got that little cushion of a few points and two home games to play.
"London Irish don't have a lot to play for now, but you don't expect professional players to roll over and give you a freebie."
Saracens raced into a 28-10 lead in Sunday's heavyweight showdown at Allianz Park, but Northampton replied with late tries from Luther Burrell and George North in a spirited fightback.
"The one positive that came out of the game is that we played that badly against a team like Saracens but were still in it at the end," Wood said.
"We looked confused at times, but we will be one hell of a team when we get it right."