If club medicos breathed a sigh of relief after the conclusion of the most brutal Origin series in recent memory, Round 20's action did its best to prove that relief premature, with Sonny Bill Williams, Peter Wallace, Jarrod Mullen, John Sutton and potentially Sam Burgess the biggest casualties out of the weekend.

The Roosters', Rabbitohs' and Panthers' premiership credentials all took a battering at the weekend, though Penrith are the hardest hit by the loss of co-captain and offensive general Wallace for the rest of the year with a ruptured ACL.

Wallace's injury sustained in their upset loss to Cronulla leaves the Panthers' playmaking stocks wafer-thin, with back-ups Isaac John and Tyron Peachey already ruled out for the rest of 2014, leaving youngsters Bryce Cartwright, Matt Moylan and former Tigers and Eels fringe first-grader Tom Humble as the most likely options to partner Jamie Soward in the halves.

The Rabbitohs too are counting the cost of their Monday night win over the Raiders, which came without the services of captain John Sutton for all but seven minutes after he left the field with ligament issues in his right knee. Sutton is expected to miss three weeks, while Burgess will have scans today on a shoulder complaint that forced him from the field midway through the second half.

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The reigning premiers also limped back down the M1 after their upset loss to the Knights bearing the news that their most destructive forward, rugby-union bound Williams, would be absent for three to four weeks with a fractured thumb, while utility Mitch Aubusson is also out for a couple of games with a high ankle sprain. 

The news was offset somewhat by the welcome sight of NSW three-quarter Michael Jennings training strongly on Monday, and a likely inclusion for their home clash against the Dragons having recovered from the back injury sustained in Origin II, though winger Daniel Tupou remains a few weeks away.

St George Illawarra will also be without centre Dylan Farrell as they continue their late-season charge toward the semis, after the luckless three-quarter tore his left pectoral in NSW Cup on Saturday, having only recently returned from the same injury to his other pectoral muscle, while the Knights are also expected to be without five-eighth Jarrod Mullen for anywhere between one and four weeks as a result of the torn abdominal muscle that kept the playmaker from returning for their second half turnaround against the Roosters.

The Cowboys and the Bulldogs however, two clubs that have been hit hardest by injuries over the middle third of the season, came out of their Saturday night clash unscathed and are set to welcome back a number of influential players in the coming weeks.

North Queensland enforcer James Tamou was cleared of any serious damage after being rushed to hospital with a suspected neck injury suffered midway through the first half of the Cowboys' win over the Dogs, and will line up against the Titans on Saturday. He could well be joined by fellow Kangaroos prop Matt Scott, and back-rower Gavin Cooper, who are both slated to return from lengthy stints on the sideline due to cheekbone and hip injuries respectively.

The Bulldogs meanwhile are set to welcome back Josh Morris (knee) for their Friday night clash with the Panthers, while props David Klemmer (ankle) and Aiden Tolman (hamstring) will also return within the next fortnight.