Concussed Haskell out of Toulouse clash
The 31-year-old, capped 70 times since making his England debut in 2007, has a concussion which he suffered just 36 seconds into his comeback from a toe injury in last Sunday's 22-16 Premiership win over Leicester.
"James is fine within himself, but he took a significant bang to the head on Sunday and we don't feel it right to push him to meet the tight deadline for a six-day turnaround," said Wasps Director of Rugby Dai Young.
"We would obviously all like for James to be involved in our big game against Toulouse, James included, but the most important thing is for him to feel completely right and under no pressure to make the game this weekend.
"This is the first time he has suffered the concussion and we have told him to take extra time, with the aim of being fit for Zebre in the final pool round."
Wasps, Toulouse and Irish province Connacht – who play pointless Zebre – are all on 13 points going into this weekend's penultimate pool matches with only the side that finishes top guaranteed a place in the knockout stages.
Elsewhere, the injury updates on Joe Launchbury, Elliot Daly and Tommy Taylor are positive, with all three being in contention for selection this Saturday.
