Winger Joe Tomane and prop Laurie Weeks have been ruled out of Australia's Rugby Championship squad for up to three weeks due to hamstring strains.

They will miss the Wallabies' opening two matches against New Zealand, which double as Bledisloe Cup clashes, in Sydney next Saturday and in Auckland on August 23.

Weeks aggravated an injury at training on Friday, while Tomane, who missed the June series against France with a broken cheekbone, suffered a fresh injury.

New South Wales Waratahs prop Paddy Ryan and Melbourne Rebels winger Tom English have been called into the squad as replacements, coach Ewen McKenzie said.

"It's disappointing to lose Laurie and Joe at this point, but ... we're going to continue to take a pragmatic approach and give guys with issues the chance to focus solely on their rehab before rejoining the squad," McKenzie said in a statement.

"We don't expect them to miss more than a couple of weeks, and when they become available for selection once again we'll know they are healthy and ready to contribute."