The injury-ravaged Saints have lost five of their last six league games - hardly form to worry Franklin's Gardens visitors Wasps on Friday night.
And Grayson said: "The Premiership is a squad event, and ours has been tested to the maximum this season.
"It has taught us that everybody in the squad has to be capable of doing the job."
Saints' crippling midfield injury crisis has started to abate with centre David Quinlan returning after five weeks out for the Wasps clash, although the likes of Bruce Reihana, Jon Clarke and Ben Cohen remain sidelined.
Saints conceded 127 Premiership points last month, and current results suggest they could find themselves heavily involved in a relegation scrap this term.
Wasps, though, are buzzing following two landslide Heineken Cup successes against Treviso, and they hand teenage centre Dominic Waldouck his first Premiership start in a side captained by fly-half Alex King.
A Wasps victory in the east midlands would pile pressure on 11th-placed Northampton, especially if bottom club Worcester close a seven-point gap behind Saints by defeating London Irish at Sixways.
Worcester have strung together a four-game unbeaten run in all competitions, and Warriors rugby director John Brain said: "The spirit and confidence within the camp has been transformed. The guys are in a pretty buoyant mood.
"It will be a very difficult match against London Irish, but we are a lot more confident going into this game than any other this season."
Harlequins hope to maintain their recent Premiership resurgence by toppling Saracens at the Twickenham Stoop on Frieday night, where the visitors give England flanker Richard Hill his first league appearance since suffering a serious knee injury 18 months ago.
Quins will need to recover from back-to-back European Challenge Cup defeats against Bath that left Dean Richards reflecting on poor finishing.
Richards said: "We created six or seven genuine try-scoring opportunities against Bath last weekend, although we only converted one of those.
"We only had ourselves to blame for fluffing a number of those, and we must ensure we are more clinical and patient in future matches."
Elsewhere, leaders Bristol take a much-changed team to Leicester - key performers like Shaun Perry, Mark Regan and Gareth Llewellyn are all on the bench - so Gloucester could go top if they beat Kingsholm visitors Newcastle and Bristol suffer only a second league defeat of the campaign.
Newcastle rugby director John Fletcher said: "Gloucester don't lose many games at Kingsholm, and we know we are up against a good side, but we are not daunted by it.
"We are excited by the challenge, and most of our best rugby this season has actually come against the better sides in the league."
Champions Sale once again have injury and illness problems ahead of the trip to Bath, with scrum-half Richard Wigglesworth, prop Stuart Turner and flanker Magnus Lund joining an already lengthy casualty list.
Bath, meanwhile, have confirmed Australian Steve Meehan's appointment as head coach after spending the first four months of this season in an 'acting' capacity.