Ziebell missed last Friday night's win over Hawthorn with knee soreness, but Scott said Ziebell's training on Monday suggested he was a good chance to return against the Saints.

"He ran really well on Monday. He'll do some more running today, and I think he'll still be a fitness test probably tomorrow as to whether he's going to play or not," Scott told reporters at Arden Street on Wednesday.

"But the way he looked Monday, I'm optimistic, but not certain.

"He'll have to prove his fitness by Thursday when we put the teams in. We won't be giving him right up until the last minute given he's already missed a week."

Scott said Daniel Wells and Nathan Grima, who have been sidelined by foot injuries since rounds five and seven respectively, were getting closer to returning.

North listed Wells as being three weeks away from playing last week and Grima's return date as indefinite.

But the Roos coach said it would be hard to be predict the pair's likely return dates with any accuracy until they returned to full training.

"They've still got some hurdles to jump, but both are improving week by week," Scott said. 

"I feel a bit for our medical guys because everyone in this industry wants a return date, and a lot of the times they've got to guess.

"My focus is on getting them both back into full training, and then once they're in full training we can put a return date on them.

"They're both really important players. We'd love to have them back, but we'd be foolish to rush them back and lose them for the rest of the year because we brought them back too early."

Scott said Wells had been "very frustrated" at times during his recovery given he was originally expected to miss one or two weeks, but was now far more optimistic and "not far away" from rejoining full training.

Scott played a straight bat to questions about the AFL Tribunal decisions relating to Roos vice-captain Drew Petrie's clash with Hawk Brian Lake last Friday night.

Petrie received a reprimand on Tuesday night for making unnecessary contact to Lake's face, but was successful in having his carryover points quashed.

But Lake, who placed Petrie in a choker hold in the third quarter of Friday night's game, was suspended for four matches.

Scott said the Roos had wanted to defend Petrie at the Tribunal and ensure he went into the latter part of the season without any carryover points hanging over his head.

"So the result (of the Petrie hearing) was good for us," Scott said.

But Scott preferred not to comment on whether Lake's penalty was appropriate.

He also said he was unaware whether Lake had apologised to Petrie, saying it was "irrelevant" to him. 

Scott said defender Aaron Mullett had responded well to his demotion to the VFL last round and was "right back in contention for selection" against the Saints, along with first-year midfielder Trent Dumont, who is yet to make his AFL debut.