The Roosters may be forced to defend their premiership without a recognised hooker, while South Sydney are set to welcome skipper John Sutton back when the sides clash on Thursday night.
Roosters hooker Jake Friend had surgery on Sunday to find and identify a source of bleeding after being diagnosed with a haemothorax. The Roosters said the surgery was "successful".
"Jake remains in hospital and has shown marked improvement in the past 24 hours," a statement read. "It is anticipated that Jake will be discharged within the next 48 hours."
It is unclear when Friend will return to the field but he is expected to miss at least the Roosters match on Thursday. Mitchell Aubusson is set to be named in the No.9 jersey as back-up hooker Heath L'Estrange still recovers from cartilage damage to his knee. L'Estrange – who hurt his knee two weeks ago – is expected to return to full training on Tuesday after the club originally indicating the injury would sideline him for at least a month.
South Sydney will be sweating on the fitness of Sutton, Sam Burgess (ribs), Greg Inglis (hip) for the potential minor premiership showdown. Their inclusion would leave South Sydney relatively injury free heading into the finals series.
Injuries are starting to mount for the first-placed Sea Eagles after Jamie Buhrer joined Glenn Stewart on the sidelines for the rest of the year after rupturing his anterior cruciate ligament. Hooker Matt Ballin is also battling to keep his 190-game streak going after a corked thigh. Buhrer doubles as Ballin's understudy at times during games; Jayden Hodges is the likely replacement.
Justin Horo is expected to come into the starting side for Buhrer, while Tyson Andrews could return to the bench.
Penrith have a long list of injury woes with the likes of Kevin Kingston (knee), Elijah Taylor (knee), Bryce Cartwright (fibula), Peter Wallace (knee), Tyrone Peachey (pectoral) sidelined for the rest of the season. James Segeyaro could return from PNG following his father's death in time for the Panthers clash against the Warriors on Sunday night.
The Storm have no big guns absent, while the Warriors' injury ward is relatively small.
Canterbury have a growing list with internationals Sam Kasiano (ankle) and Frank Pritchard (pectoral) sidelined. Pritchard could be back before the end of the season, while Chase Stanley (shoulder) and Tim Browne (head) and Lloyd Perrett (ankle) will be fit should Canterbury go deep into the finals series.
Veteran centre Willie Tonga (spine) could return for the Eels in what may be his NRL swansong, against the Raiders on Saturday.
THE CASUALTY WARD
Manly
Glenn Stewart (ankle), Jamie Buhrer (knee) season. Matt Ballin (corked thigh), Brenton Lawrence (knee) in doubt.
Rabbitohs
John Sutton (ankle), Sam Burgess (ribs), Greg Inglis (hip) in doubt.
Roosters
Jake Friend (haemothorax) season in doubt. Heath L'Estrange (knee) at least two weeks.
Panthers
Kevin Kingston (knee), Elijah Taylor (knee), Bryce Cartwright (fibula), Peter Wallace (knee), Tyrone Peachey (pectoral), Isaac John (Achilles), George Jennings (elbow), Shaun Spence (concussion), all season. Brent Kite (pectoral) at least two weeks.
Storm
Matt Duffie (knee), Slade Griffin (knee) season. Kenny Bromwich (elbow) in doubt.
Bulldogs
Sam Kasiano (ankle), Jacob Loko (knee) season. Tim Browne (head) two weeks, Chase Stanley (shoulder) two weeks, Frank Pritchard (pectoral) could return, Lloyd Perrett (ankle) finals week three.
Cowboys
Brent Tate, Cameron King, Lachlan Coote (all knee) season.
Broncos
Josh Hoffman (ankle) two weeks, David Stagg (foot), Mitchell Dodds (knee) indefinitely.
Warriors
Glen Fisiiahi, David Fusitu'a (both shoulder), Jerome Ropati (broken jaw) season.
Eels
Nathan Peats (knee), Lee Mossop (shoulder), Taniela Lasalo, Mitch Allgood (knee) season. Willie Tonga (spine), Manu Ma'u (arm) and Bureta Faraimo (knee) in doubt.
