Sullivan was whacked during the green and golds’ opening round win over Bathurst St Pat’s, the hit cracking one of his ribs and leaving CYMS minus its chief play-maker for almost an hour of Sunday’s season opener.

The four-time premiership winning captain-coach says he’s expecting to be out for about a month, but given he’s not experienced an injury like this one there’s a fair bit of uncertainty surrounding recovery for the former NRL rake.

“I’ve cracked a rib and there’s a bit of cartilage damage there, I’m looking at about four weeks but this is the first time I’ve injured my upper body, touch wood it’s the only time,” he said.

The loss of Sullivan isn’t the only blow for CYMS, with young centre Lachie Munro suffering ankle ligament damage last Sunday.

Munro’s place in the green and golds three-quarter line will be taken Joe Lasagavibau, while Sullivan’s replacement will be another centre, Dom Maley.

Maley’s return to premier league is a late one, the gun outside back initially indicating he wouldn’t be playing in 2017.

Although unexpected, his inclusion is a welcome one for Sullivan searching for a halves partner for five-eighth Luke Petrie.

“We’ve had a lot of great faces return late this pre-season, Dom Maley, Sam Hill, Kyran Bubb, Nick Law, these guys will be great for us,” Sullivan enthused.

“They haven’t had much a pre-season, but I’ve said it a few times, with some of the really long years we’ve had, that might not be a bad thing.

“Dom started in the second-row last week but with Brendon (Cousins) back we can shift him.

“We’re probably flush for backs, but we’re down in the backrow. Brock (McGarity) did a great job for us last week getting through 76 minutes.”

Sullivan said the club would keep an eye out for another forward to bolster CYMS’ backrow depth before the transfer deadline of June 30.

CYMS take on Panthers on Thursday night at Wade Park, the crash brought forward to avoid the Easter weekend.

Both sides coming off a big win in round one wins, but Sullivan believes the beefed-up Panthers head into the clash deserved favourites.

“They are, no doubt,” he said.

“I think a few people would probably be surprised with our result. I don't think teams expected us to be big winners against St Pat’s.

“For me though Oberon is the stand-out side. I know Bran (Tigers coach Luke Branighan) well and he’s got them doing some smart things.”

Kick-off between CYMS and Panthers is at 9pm.