Leon Holden admits Wasps are heading into a season-defining stage of their Aviva Premiership campaign.
Wasps are currently eighth in the table, but only five points behind Sunday's opponents Northampton, with Saints occupying the fourth title play-off place. After visiting Franklin's Gardens, Wasps go to London Irish next weekend, then host Leeds Carnegie and Bath before finishing their regular season league campaign at Exeter.
"The game against Northampton this weekend marks the start of a crucial period for us in the Premiership," said Holden, who has taken interim charge at Wasps following the departure of his fellow New Zealander Tony Hanks as rugby director last month.
"Starting with two away games against Northampton and London Irish, we then welcome Leeds to Adams Park and head to Twickenham for our St George's Day Game against Bath.
"We must take every game on its own merits, but a good run of results in this block of fixtures will define our season."
England lock Simon Shaw returns to domestic duties with Wasps on Sunday, and hooker Rob Webber is back after a long-term injury. There are also starts for centre Steve Kefu, who partners Riki Flutey in midfield, and prop Zak Taulafo.
Northampton's England quartet of Ben Foden, Chris Ashton, Dylan Hartley and Tom Wood, meanwhile, make an immediate reappearance in Premiership action following their Six Nations rigours.
Northampton have lost their last three home league games, but victory at Leeds last time out lifted Saints back into play-off territory, with rugby director Jim Mallinder claiming: "It wasn't just a victory, but a much better performance.
"We got our basics right and dominated up front. We played aggressively and took our opportunities well."
Saracens, thriving on the back of six successive wins in all competitions, should be too strong at Vicarage Road on Sunday for a Newcastle side that can claim just one Premiership away victory this season.