update: Ross, Marshall, Cronk, & Johns

Australia's front row stocks have been dealt a blow with Kangaroos hopeful Ben Ross suffering a potentially season-ending knee injury during Cronulla's emphatic 40-12 NRL victory over Penrith at CUA Stadium last night.

Sharks wingers Luke Covell and Darren Albert both scored doubles in the seven-tries-to-two win, but the strong performance was soured by a suspected torn cruciate ligament to Ross.

Wests Tigers star Benji Marshall has been cleared to play for New Zealand in next Friday's Anzac Test, but doctors have warned he risks further injury if he plays for more than an hour of the match against Australia.

Orthopaedic specialist Des Bokor has cleared Marshall to play for the Kiwis providing he gets through a strict rehabilitation program next week, but has advised the young five-eighth not to play for more than 60 minutes. Marshall may even avoid end-of-season surgery after making a quicker-than-expected recovery on his injured shoulder.

In tonight's games, North Queensland play the Sydney Roosters in Townsville, Brisbane host Canberra and Melbourne take on St George Illawarra at Olympic Park.

Melbourne Storm will give star Cooper Cronk until this morning to prove his fitness for tonight's NRL match with St George Illawarra. Cronk has been battling a shoulder injury all week, but successfully completed training last night. The club is waiting to see how the 22-year-old pulls up today before deciding whether he will play.

Newcastle captain Andrew Johns is set to make his NRL return against South Sydney on Sunday with Knights surgical specialist Neil Halpin saying he thinks the champion halfback will play.

The Knights will make a final decision on Johns's fitness after the side's training session this morning. But after inspecting the Knights skipper yesterday, Halpin says Johns is a good chance of playing. Johns, who wants to make his representative football farewell for Australia in next Friday's Anzac Test against New Zealand, missed last weekend's heavy loss to Melbourne after sustaining an ankle injury against North Queensland in round six.