NO TIMEFRAME has been given for North Melbourne forward Jarrad Waite or impressive runner Billy Hartung's absence, with both to miss Sunday afternoon's clash with Essendon, but tagger Ben Jacobs is expected to return from concussion.

A lingering calf injury is bothering Waite, 35, while Hartung has suffered a left hamstring strain.

However, Jacobs should play in the clash at Etihad Stadium after suffering delayed concussion.

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"He'll train today (Thursday). I'd love to say that he's going to play. That's certainly my expectation, but with these things we just need to wait and see how he pulls up," Roos coach Brad Scott said at Arden Street.

"He trained really well last week too. Even if he trains really well today, then we'll just assess him (Friday) morning."

There is no rush on Waite's return as he deals with yet another stint on the sidelines.

"We'll assess next week as he starts to tick boxes in terms of his recovery," Scott said.

"My instruction to our sports science and medical team has been 'When you think he's right, give him a few more' because we just need to make sure that when he's back, he stays back."

Scott said he doesn't yet know when former Hawk Hartung will return.

"Billy's got a hamstring strain that, to be honest, we're still assessing, but it's certainly a strain that will keep him out of this week's game," Scott said.