Cronulla are hopeful Braydon Trindall will only miss one NRL match after scans confirmed the halfback had suffered a low-grade hamstring tear.
Trindall failed to get through the Sharks' win over South Sydney last Saturday night, but Cronulla officials believe he may only miss Friday's trip to Gold Coast.
The injury leaves Cronulla without both of their first-choice halves, given Nicho Hynes is also sidelined until the eve of the finals with an ankle injury.
Hooker Blayke Brailey will come into the halves to replace Trindall, partnering Daniel Atkinson. Cameron McInnes will in turn start at No.9.
Brailey previously filled in at halfback in the Sharks for their win over Melbourne earlier this year, and made clear earlier this week he can be comfortable playing there.
"I actually came through the grades playing halves. It wasn't until under-18s that I stopped," Brailey said.
"It's been a couple of years now. I am sure I will have a bit of training this week. It's going to be an interesting week."
The Sharks have also put Braden Hamlin-Uele on ice for Friday's match due to knee soreness, and are still without prop Tom Hazleton (foot) as they fight to stay in the top four.
Elsewhere, Brisbane have turned to Josh Rogers at five-eighth for Saturday's clash with North Queensland, with Ezra Mam unlikely to play again this season after suffering an ankle injury.
Payne Haas is also battling to return this season with a foot injury, as the Broncos' nightmare campaign continues.
The news is better for Manly as they push to wrap up a finals spot.
Winger Lehi Hopoate will return from a fractured eye socket against Canberra at Brookvale Oval on Saturday, just three weeks after suffering the ugly injury.
Lachlan Croker is also back at No.9 after spending three months following a concussion, while Jason Saab and Reuben Garrick have also recovered from head knocks.
Their fitness comes as Haumole Olakau'atu returns from suspension in the back row against a Raiders side that have lost Zac Hosking to a shoulder injury.
Canberra coach Ricky Stuart has recalled five-eighth Ethan Strange after opting to rest him from Sunday's loss to Canterbury.
South Sydney five-eighth Cody Walker will return from a calf injury against Melbourne on Thursday night.
The table-topping Storm will be without Eliesa Katoa due to a knee injury, with Nelson Asofa-Solomona to move to the second row and Tui Kamikamica (groin) back at prop.
Daine Laurie will also return at fullback for Penrith against Parramatta with Dylan Edwards (knee) still sidelined.
The Dolphins will have Tevita Pangai Junior and Kodi Nikorima back against Gold Coast, with Jamayne Isaako also hoping to overcome an ankle injury.
And Adam Doueihi will come back into the Wests Tigers side at centre for Sunday's trip to Newcastle, with Justin Olam ending his season early to undergo knee surgery.