KNIGHTS coach Brian Smith said he would not use his team's disrupted preparation as an excuse if they came up short against South Sydney at Bluetongue Stadium tomorrow.

Newcastle will be without NSW representatives Jarrod Mullen (ribs) and Steve Simpson (hamstring) for three weeks each and back-rower Cameron Ciraldo (ankle) indefinitely after all three suffered injuries in their 24-12 victory over Cronulla on Monday night.

Injury or illness clouds hover over former Rabbitohs Ben Rogers and Adam MacDougall (both virus), back-rower Cory Paterson (wrist and neck) and prop Richie Fa'aoso (hamstring).

Smith named a bench of Matt Hilder, Keith Lulia, Fa'aoso and George Ndaira, but props Tim Natusch and Danny Wicks and utility Marvin Karawana have trained all week and the coach will finalise his side at a closed training session today.

Lulia is on stand-by for MacDougall, Karawana for Rogers, and Natusch and Wicks are in the mix for Fa'aoso. Even if Fa'aoso is cleared, he could be joined by Natusch or Wicks at Lulia's expense to give the Knights a second front-rower in the interchange rotation.

Smith is leaning towards ruling Rogers and MacDougall out if tomorrow is hot.

"It's getting close to to the wire about making a call there. Maybe some of that call will be made there by the weather conditions on Sunday afternoon," Smith said yesterday.

"If it turns out to be very hot, we'll probably go without them. We'll probably make an interim decision between now and then and finalise it on the day."

Smith said it was up to the 17 players who take the field to carry the same attitude and commitment into tomorrow's game as those who toughed it out against the Sharks.

"It's hard, but it's not as hard as it once was. All these guys are full-time players and we've had 100 sessions or more since the pre-season started," he said.

"Last week our four bench players played over 200 minutes and they won the game for us. Just by definition, as soon as they come onto the field there's some adjustment going on within your team, so it's a factor in footy today.

"From my point of view, I think we've done more than enough practice and it's just a big club day coming up for us on Sunday. We're going to have eight or nine of our top 25 missing and we're still going there to win.

"We're not going there to cry if we get beaten because we had so many players out. We're going there to try to win the game and certainly to do the absolute best we can, and that's what our guys did on Monday night. We had plenty of reasons to lose that game the other night, and they just kept finding the one way they could to win, and they did it."

Forward Chris Houston said players would prefer to know well in advance who was playing alongside them each week, "but as long as we get the last session in all together, roughly, with the blokes who are playing that week, then we're confident going into the game that we can do our best and get the win".

Souths coach Jason Taylor will check Rhys Wesser's fitness today after the former Penrith fullback suffered a knee injury in their 14-8 loss to Parramatta last Friday night.

Smith feared the triple threat of Rabbitohs halfback Chris Sandow, hooker Issac Luke and bench spark plug Craig Wing.

Sandow has missed 18 tackles in the Rabbitohs' first two games against the Roosters and Eels, but he and Luke will test Newcastle's defence all day if given enough latitude.

Wing is making his first NRL appearance this year after off-season groin surgery and a NSW Cup game for North Sydney last Saturday.

"I think we'll need to be very good on their halves and their hooker. Issac Luke is a real focal point for their attack and their go-forward," Smith said.

"He makes some really good decisions with his dummy-half running, and he brings those big forwards they've got onto the ball well."