NORTH Melbourne won't be worrying about how Essendon responds to this week's news that its anti-doping nightmare is not over when the teams clash at Etihad Stadium on Friday night, coach Brad Scott says.

Scott said the Roos would be focused solely on their own performance.

Essendon has shown remarkable resilience in the 27 months that 34 past and present players have had to live under the spectre of possible anti-doping bans.

During the saga the Bombers have seemingly ridden a backs-against-the-wall mentality to some stirring wins:

• Defeating Fremantle at Domain Stadium in round three, 2013, after coach James Hird had been pressured to step down
• Beating West Coast in Perth in round 14, 2013, after captain Jobe Watson said he believed he had been given AOD-9604
• Smashing North in round one last season after a controversial television interview by Hird's wife Tania.

Speaking to reporters on Wednesday, Scott would not speculate on whether the World Anti-Doping Agency's appeal against the AFL Anti-Doping Tribunal decision clearing the 'Essendon 34' would inspire the Bombers again on Friday night.

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"If we take our focus off what's important to us and start focusing too much on our opposition we'll take our eye off the ball," Scott said.

"All questions about Essendon are best directed to them. I'm here to focus on my team and get us up for Friday night.

"We've had some areas of the game that have let us down so far this year, so it's really important that we fix that up.

"We're really confident that if we do that we can tackle any opposition."

Scott said Daniel Wells would probably miss another two or three games with the Achilles tendon injury that has sidelined since round two, and could not rule out a longer absence.

"It's really frustrating for Daniel and it's frustrating us that we can't give a definitive timeframe on his return to play, and as it sits at the moment we're going to list him as indefinite," Scott said.

Asked whether Wells' absence could drag on for up to eight more rounds, Scott conceded he could not rule it out.

"I doubt it, but again I don't want to be proven wrong," he said.

"He's got some symptoms in his Achilles. We don't think they're at the serious end, but they do continue to linger, so it will just be a matter of when he can function and get out and train.

"Then it will be an issue of match fitness to make sure that he's done enough work before he plays so that he's absolutely ready to perform at his best."

Asked whether Wells' career was in doubt, Scott was adamant the 30-year-old's Achilles was structurally sound and the "significant inflammation" around it would not be a long-term issue.

Scott said midfielder Nick Dal Santo was due to have a check-up with his surgeon on Wednesday after undergoing surgery on his hamstring last month.

"He feels like he can run at a reasonable speed now, it will just be a matter of ticking the boxes and progressing from here for Nick," Scott said.

"We're really rapt with his progress so far."

Jamie Macmillan (Achilles) was a late withdrawal from North's clash with Richmond last Saturday, and has been sidelined for all bar two games this season.

Scott said the Roos would most likely select the utility for Friday night's clash against Essendon if he completed training on Wednesday, but reserved the right to make a late withdrawal if he was not 100 per cent fit before the game.

The Roos coach said key defender Nathan Grima (back) was expected to return between rounds 11 and 14 after he completed a "mini-pre-season".