He said: "Fans can expect a response. We're in a position where we are just scrapping for everything.
"We didn't show enough urgency and intent last week so we need to put that right against Quins."
The 2012 Aviva Premiership champions will be missing several stars in England's Danny Care, Chris Robshaw and Mike Brown.
And although Grove knows they have quality resources to fill-in, he believes it is an opportunity for Warriors to take advantage.
He explained: "It's always a good time to play the top sides when their internationals are away. Robshaw, Brown and Care are all world-class players and Care makes that team tick.
"They have decent personnel stepping in but there will certainly be a few things missing and we can capitalise on that this weekend."
Warriors were undone by Quins back in September after an intense display from the visitors at Sixways.
And Grove knows his side will have to be switched on this weekend to avoid a repeat result.
He admitted: "If they get any opportunity to speed the intensity of the game, whether it's a quick-tap penalty or a quick lineout, they'll do that.
"Care is a catalyst for them in terms of picking up that intensity and it's something they are still capable of doing even though their big guys are missing.
"It's simple things we need to do like being switched on and not turning our backs if they take a quick penalty, and we need to do it from the off."
If Warriors are to pick up victory this weekend, the centre insists his side will have to get the fundamentals right first and foremost.
He concluded: "If we get our set-piece right then we have a platform in which to play the game. Our lineout and scrum is crucial.
"They are the fundamentals and after that it's our kicking game, discipline and our breakdown but ultimately our set-piece is vital.
"There are 35 points out there still to play for and we will scrap for each and every one."