Hooper's hamstring injury, sustained on international duty, brings an end to his run of 79 consecutive Super Rugby matches for the Waratahs though he hopes to make a return for the postseason.
"He's hugely valuable and I think it's going to be quite a big test for the Waratahs," Haylett-Petty was quoted as saying by the Australian Associated Press on Wednesday.
"It's been five or six years since he's missed a game and he's probably the main voice in that group so it will be interesting to see how they go without him."
While the Rebels have their own injury concerns, with Will Genia (arm) and skipper Adam Coleman (adductor) both out, they have played at times without the key duo whereas Hooper has only missed 53 minutes in 93 games since joining the Waratahs in 2013.
Haylett-Petty, who is set to return to fullback after playing wing for the Wallabies in the 2-1 series defeat to Ireland, said he was pleased to have been able to show his best form in recent games after an injury-hit season.
"Obviously early on in the season it didn't go the way I'd hoped but I've played five games now and I'm feeling good. I feel like I'm starting to have some form and am really enjoying being out there," the 29-year-old said.
The defeat to Six Nations champions Ireland was tough to take but the Wallabies had shown in the series that they had the potential to improve, he added.
"If anything this one hurt more than most as it was so close so it's hard to look back at all the little missed opportunities," he said.
"But they're the second team in the world so to be so close with so much room to grow I suppose is exciting."
(Reporting by John O'Brien in Singapore; Editing by Peter Rutherford)
Share
